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Username Post: 2005 Impala issues        (Topic#359245)
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-26-19 09:29 AM - Post#2782930    

I have a 2005 Impala 3800 engine with 240,000 miles....Just had new intake gaskets installed, EGR tube unclogged of carbon, new catalytic converter installed to try to solve issue with the EGR and Catalyst monitors not completing. I had a misfire issue earlier in year that caused a P0420 code...also had EGR code for poor flow....I installed new EGR valve and cleared codes a couple of times.

Since then, the EGR and CAT monitors will not go to completed status after 3,000 miles of driving....so I recently had all the work listed above done....Cat
exhaust odor smelled like a car without a cat....exhaust would burn the eyes if you stood by tailpipe...Now with new Cat, exhaust smells much cleaner with a subtle sweet odor but my EGR and CAT monitors are still not going to completed status.

What could cause monitors to "hang up" and not complete with no check engine codes showing?




 




Shepherd 
Frequent Contributor
Posts: 2067

Loc: Lake George, NY
Reg: 11-11-15
12-27-19 01:38 PM - Post#2783032    
    In response to dwi189

If you have any pending codes related to those components the monitors will not reset, I have seen this in my shop and wound up having friend reset them with a professional scanner. Is this a state inspection issue?



 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-27-19 07:15 PM - Post#2783042    
    In response to Shepherd

I do not see any pending codes....Upcoming Inspection is the issue....1 incomplete monitor is allowed for passing.

I had new converter installed a few days ago.....I am now down to 2 incomplete monitors...EGR and Catalyst....It does seem like the Evap monitor has completed much quicker this time around so I am hoping that with the new converter, the monitor for that will go ready fairly quickly now....I just put a new EGR valve on today and the EGR tube was recently cleaned of carbon.

I have also been reading up on specific drive cycles for the EGR and CAT monitors to get them to go ready.....If one or both go to ready status in the near future, then perhaps the new parts will have helped.



Edited by dwi189 on 12-27-19 07:18 PM. Reason for edit: No reason given.

 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-28-19 12:27 PM - Post#2783081    
    In response to dwi189

Sounds to me like the EGR monitor is the issue.
EGR should clear on the first Open to Closed loop drive.
The Catalyst will not clear without the rest being complete.
Is it going into closed loop?
What is the coolant temperature? Is it getting hot enough?
I would not go any farther with the catalyst until the EGR is resolved

Old School GM fan FOREVER


 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-28-19 01:06 PM - Post#2783086    
    In response to rockfangd

It is getting up to normal temperature as far as I can see on the gauge....Usually before it warms up to temperature, the lockup torque converter will not lockup....When I had coolant temp sensor issues a few years ago, my torque converter took a long time of warmup before it locked up.....

It locks up very quickly and the gauge responds quickly as well....It does seem that something is indeed causing the EGR monitor to hang up.



 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-28-19 09:46 PM - Post#2783109    
    In response to dwi189

I understand your TCC lockup.
But do not trust the gauge. The gauge is merely a way to look ok... Typically around 12 oclock normally. That can mean a range of over 20* difference.
I would do a egr test with scantool to see if the engine responds.
The more the valve is demanded open the more the engine should stumble.
If the valve is demanded open but no change is seen I would think the valve or wiring to valve is not functional

Old School GM fan FOREVER


 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-29-19 04:08 AM - Post#2783114    
    In response to rockfangd

I just ordered a wireless bluetooth OBD2 adapter to run torque pro on my phone.....I don't know yet if torque pro has the ability to monitor EGR flow or not.

One interesting thing....I bought a new EGR valve from Autozone...a Valucraft brand as opposed to a Duralast that was already in it....They both looked the same aside from color. It was listed as being proper for my car. I installed it a few days ago.

However, after installing the Valucraft, I soon got a P0405 code with a flashing CEL while driving on highway....I stopped at an Advance Auto and bought a new Carquest EGR valve which was twice the price of the Autozone valves....I changed the valve in the parking lot and drove it and the code went away.

New valve still has not solved the monitor not completing situation.

One other interesting note....When the CEL light came on for that P0405, it showed the EGR monitor now as 'ready'.....so I thought the monitor issue was solved.

However after changing the valve and after the CEL went out, I checked the monitor status again and the computer "took away" the ready status for the EGR monitor and it is showing incomplete again.

I am totally baffled....I have never had an issue with this car prior to this where certain monitors would not update.

Prior to outting the valucraft valve in, I unplugged the wiring connector for the valve and started engine to see if it would throw any codes which it did so computer was detecting the EGR connection.

The monitors behaved the same way as well....When CEL went on, the EGR monitor went to comoleted status and then when I hooked wire back up and light went out, monitor reverted to incomplete.



Edited by dwi189 on 12-29-19 04:19 AM. Reason for edit: No reason given.

 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-29-19 04:11 PM - Post#2783150    
    In response to dwi189

Good info here.
Aftermarket egr valve... What did you do with the original.
I have not had good luck with aftermarket valves. More than once have I run into issues there.
When a system throws a code it will complete the monitor. It recorded the parameters and saw a fault and therefore completed the monitor.
How long have you driven since clearing codes and not having a returning CEL?
Important now to not trip the light unless there is actually a problem as it will only take longer to clear monitors.


Old School GM fan FOREVER


 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-30-19 03:43 AM - Post#2783191    
    In response to rockfangd

I have driven perhaps 340 miles since clearing and resetting the monitors after replacing valve....I am currently at 3 not ready....Evap, EGR and CAT....The original EGR to the car was replaced years ago....am on my 3rd or 4th now....

Another bit of info that I am now remembering....Up until 3 months ago, I was getting a random P0401, poor EGR flow....I took valve out and cleaned it at that time and cleared the code....That is when the issues began where the EGR monitors would not update on their own.

I then had the intake manifold gaskets replaced when shop found evidence of leaking...They also cleaned out the EGR tube that runs from valve to exhaust manifold...tube was clogged with carbon according to them.

I have also heard that there is some sort of EGR passage or stovepipe on 3.8 engines that can burn through the intake...I do not know if they replaced that part or not.

As far as the monitor readiness being "taken away" after the CEL went out, I am wondering if it is because the CEL came on before the monitor had already completed....I have never checked on prior occasions whether a CEL would force a monitor to complete and remain completed.



Edited by dwi189 on 12-30-19 06:26 AM. Reason for edit: No reason given.

 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-30-19 11:21 AM - Post#2783218    
    In response to dwi189

Question.
You mention it has a 3800.
I need to think a little bit here.
Is that a wet or dry intake?
That monitor should have cleared by now.
Catalyst will not clear without it.
I am wondering if it has flow but is partially restricted, enough to not throw a code, but not enough to clear the monitor

Old School GM fan FOREVER


Edited by rockfangd on 12-30-19 06:27 PM. Reason for edit: No reason given.

 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-30-19 02:11 PM - Post#2783232    
    In response to rockfangd

Its the original 3800 series 2 engine....2005.That identification is on the plastic cover on top of the engine.

I am down to 2 monitors not ready now after the reset...EGR and CAT...Evap went complete on the drive home after an 8 hour cold soak at work today. I now have a pending P0101 which has been happening after driving down a steep hill at 40 mph using conpression braking in 2nd gear.

Usually after letting the car sit for awhile, that pending code goes away upon the next restart.

The code seems to come and go at random, mostly from descending long steep grades in a lower gear.

I replaced the MAF sensor a few months ago which made the code less frequent but did not entirely solve the issue.

I am wondering if this issue is related to or influencing the EGR monitor not completing issue.






Edited by dwi189 on 12-30-19 03:02 PM. Reason for edit: No reason given.

 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-30-19 06:29 PM - Post#2783250    
    In response to dwi189

Gotcha. Last era for that engine.
Reread my above post. Am looking further into it

Old School GM fan FOREVER


 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-30-19 06:33 PM - Post#2783251    
    In response to rockfangd

I just thought of something. This is a big one.
Are you driving it with anything hooked up to the ALDL? If you are disconnect it. As weird as it may sound I have had a reader or scantool interfere with the monitors. More than once I have run into this

Please review this.

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.
Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.
Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.
Reprinted on OBDII web site courtesy of General Motors Corporation
© General Motors Corporation

[ OBD-II Home ]



Old School GM fan FOREVER


Edited by rockfangd on 12-30-19 06:36 PM. Reason for edit: No reason given.

 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-30-19 07:38 PM - Post#2783258    
    In response to rockfangd

I do have a code reader hooked up to my OBD-2 port and I keep checking it to look for completed monitors and the monitors have been completing with it hooked up.

If there is still a partial blockage in the EGR system, that would be a possibility if the repair shop did not get everything cleaned out when they did my intake manifold gasket replacements.

The tech said that they found the EGR tube which runs from the EGR valve to the exhaust manifold clogged up with carbon and they cleaned it out.

They were confident enough at the time that my monitors would complete after I drove it a few days.....which the monitors didn't.

I have "loosely" tried the drive cycle already.....problem is that the highway is a couple of miles from home and from work and if I slow down too much, I hold up traffic.

I am expecting my OBD2 wireless bluetooth adapter to arrive tomorrow so that I can hook it up to torque pro.

Torque pro is supposed to be able to monitor my engine functions including whether the monitor tests are running so I will have to see what happens with that and then I can monitor the drive cycle.





Edited by dwi189 on 12-30-19 07:48 PM. Reason for edit: No reason given.

 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
12-30-19 07:47 PM - Post#2783259    
    In response to dwi189

Humor me.
With nothing hooked to ALDL.
Cold start.
Idle for a few minutes.
Accelerate to highway speed 55mph or so.
Keep speed for at least 3 minutes.
Decelerate down to about 20mph not hitting the brake.
That should clear the EGR.
It make take a few attempts. If that does not get it then I would be suspicious of a non oe valve
Another thing to mention is the brake light switch. Have you had any issues with the brake lights? Especially in that era. A stuck or intermittently stuck brake switch will cause issues as well.

Old School GM fan FOREVER


Edited by rockfangd on 12-30-19 07:57 PM. Reason for edit: No reason given.

 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
12-30-19 07:50 PM - Post#2783260    
    In response to rockfangd

Ok will give that a try....My brake lights are working normally.



Edited by dwi189 on 12-31-19 03:44 AM. Reason for edit: No reason given.

 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
01-01-20 09:09 AM - Post#2783388    
    In response to dwi189

Okay...some interesting positive developments...I went out and did a drive cycle early this morning on a local interstate free of traffic due to New Years.....up to 55 and coasted down to 20 and back to 55...and my CAT monitor completed....so down to 1 Incomplete now...EGR...so good for inspection.

Another note...I have had a problem with very strong vacuum whenever I removed the oil cap with engine running...car would run rough and try to pull my hand against the oil filler.

I read about how the PCV valve could cause this....I bought a Dorman 47033 PCV valve kit.

The MAP sensor mounts onto a plastic fitting which in turn twist mounts onto the intake manifold....The kit includes the plastic fitting, a spring, two o-rings, and the PCV valve.

When I took the old one apart, I found that the spring and one of the o rings was missing on the old one.

I installed the new kit including the new map sensor mount, new spring, o-rings, and pcv valve and started the car and took off the oil cap and no more vacuum and rough idle....The car has had this vacuum issue for over 100,000 miles and I thought it was the way it was supposed to run....

Somewhere along the line, when the PCV valve was changed years ago, the spring and o ring was lost.....I have been putting new valves in improperly ever since not realizing the missing parts.

So....hopefully all is good now.



 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
01-01-20 09:20 AM - Post#2783392    
    In response to dwi189

Ok. That explains alot.
That EGR should clear though.
If you can get it inspected and the light stays out I would not worry too much.
I am hoping you have not developed other issues from the lack of vacuum source for so long.
Keep an eye on your oil level just in case

Old School GM fan FOREVER


 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
01-01-20 09:54 AM - Post#2783398    
    In response to rockfangd

I am hoping this solves the EGR issues....The car has been using oil over the past few years....The intake manifold gasket replacement seems to have cut the oil consumption down...the PCV system vacuum leak probably contributed to oil consumption as well.



 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
01-01-20 11:48 AM - Post#2783416    
    In response to dwi189

I am sure it did.
If you dont develop any leaks consumption should be better

Old School GM fan FOREVER


 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
01-02-20 09:15 AM - Post#2783492    
    In response to rockfangd

And finally this morning..0 incomplete monitors and 0 codes....took three months to sort through the pending and current codes, CEL's and monitors not completing....Hopefully it will be smooth sailing for awhile in regard to codes and monitors.



Edited by dwi189 on 01-02-20 09:16 AM. Reason for edit: No reason given.

 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
01-02-20 08:04 PM - Post#2783548    
    In response to dwi189

Beautiful.
Is it inspected?
That is always a good day

Old School GM fan FOREVER


 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
01-03-20 09:07 AM - Post#2783600    
    In response to rockfangd

Inspection is planned for within the next few days.



 
dwi189 
Newbie
Posts: 29

Reg: 02-10-09
01-06-20 01:22 PM - Post#2783823    
    In response to dwi189

The car passed its annual inspection so all is good.

Thanks for the input regarding drive cycles which helped the monitors set on the car.




 
rockfangd 
"7th Year" Gold Supporting Member
Posts: 2899
rockfangd
Age: 34
Loc: Utica ny
Reg: 04-13-10
01-06-20 07:35 PM - Post#2783866    
    In response to dwi189

Absolutely.
So glad you got it figured out.
Been there before.

Old School GM fan FOREVER


 




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