2001 grand prix help needed wont pass emissions

[bagged98]

hi everyone i have a 2001 grand prix 3.8 non supercharged car. iam trying to get it to pass emissions in my state. i have to codes coming up p0440 and p0403 one is evap other is egr. egr valve has been replaced and same with the fuel cap.the car does have 160 000 miles but runs like a champ no issues other than codes and not passing stupid state emissions.. but codes still popping up i cleared codes the other day by resetting the egr by unplugging the egr valve turning key on cleared the codes then turning off ignition right away then plugging egr back in and starting the car.the code was gone and stay gone for about 3 days then when i left this moring to go get it tested for emission ses light popped back on..so my thoughts are the car just took that long to relearn everything and kicked the light back on..what is the problem anyone? iam stumped i talked to one other person they said something about a problem with these cars and the pcm has to be re-flashed do to a reoccurring problem with the egr.anyone heard of that ?? any help would be great .thanks michael ...........ps please know what your talking about

[Tech II]

For one thing, you can't clear a code by disconnecting a sensor or by disconnecting the battery....it takes a scan tool/code reader to clear the code(not all code readers can clear codes)......

It's possible you fixed the EGR problem, but since you DID NOT CLEAR THE CODE, it's still there in history....

As for the P0440, changing the cap sometimes fixes it....but once again, you still don't know if that fixed it because the code wasn't properly cleared.....

Go to places like AutoZone, who will clear them for free......then run the vehicle and if the light comes back on, have the codes read again.....

Right now, you are just a parts changer, and hoping for the best....you have done no diagnosis, which is hard to do without a scan tool and diagnostic tree....you could have replaced the EGR, that was still good, and had a wiring problem or flow problem due to blockage.....you replaced the cap, but you could have a vent/purge solenoid problem, wiring problem, pressure sensor problem, a leak anywhere in the system(line, fuel tank, canister, etc.)......

You can continually replace parts and get lucky, or go to a garage or dealership with a good rep.....then even though it is fixed, you will have to drive the vehicle to reset all the emission flags....if they don't reset, you won't pass your test....

[olopezm]

Disconnecting the battery erased all codes in the PCM but since the problem hasn't likely been fixed the CEL came on again.

I would make sure your battery is OK first. Even when the car starts, a battery going out or low on charge can cause weird problems. You can have it tested at any autoparts store.

The EVAP code is more like a general malfunction and not necessarily a vacuum leak. I would make sure all connectors are OK including the PCM connector and wiring.

The EGR troubleshoot is a bit more complicated with the electric EGR valve installed on GM cars. Again I would make sure all connectors and wiring are OK.

Oscar.

[Tech II]

Codes do not clear by disconnecting a battery on this car!

[bagged98]

1st things 1st i said noithing about unplugging a battery please if your going to post on here read my post.. iam not a parts changer.. am CHEAP and rather not pay a arm and a leg and have a dealer screw me over thats why iam here not there. iam not using a autozone scanner or dealing with idiots behind a advance auto counter or unplugging a battery or praying to god .i own a $4,000 snap on scanner.. like i said in my 1st post ///i cleared the codes !!!! not i unplugged the battery and crossed my fingers.. and also tech 2 just unplugging the egr and clearing the codes and plugging back in did work it cleared the check engine light and light didnt come on for about 700 miles...

[Tech II]

OK, first question: How can you afford a $4000 SnapOn scanner? You don't sound like a tech.....funny, you said nothing about your 4K scanner, you said, and I quote:

"i cleared codes the other day by resetting the egr by unplugging the egr valve turning key on cleared the codes then turning off ignition right away then plugging egr back in and starting the car.the code was gone and stay gone "

That will not clear a code!

So you cleared both codes with the scanner and BOTH came back in a couple of days?

This scan tool should be able to tell you EGR pintle position and commanded position.....should also have bi-directional capabilities......have you checked this out with the scan tool?

As for the P0440....you tried a new gas cap......was there corrosion on the filler tube where the gas cap mates with it? If no and clean, and if you tightened 3-5 clicks, and fuel level is between 1/4 to 3/4 of a tank, the evap test should run......if this code reset after you, replaced the cap and cleared the codes, the cap wasn't the problem......you can make physical observations of the system, but if there is nothing obvious, the only way to find the problem is with a smoke machine and sealing the system......

[bagged98]

you have to be a tech to own a scanner ?? and yes iam a tech a body tech i do paint body and customizing ..when it comes to emissions i dont have a clue i usally rip it out and plate it in another county..lol but that is not going fly this time.. and yes i said cleared the codes... not unplugged battery.like i said..

"i cleared codes the other day by resetting the egr by unplugging the egr valve turning key on cleared the codes then turning off ignition right away then plugging egr back in and starting the car.the code was gone and stay gone "

cleared the codes meaning i turned the key on and cleared the codes right when the scanner say codes cleared turn the ignition off

i found this online somewhere and suprised when it actually work for four days and then popped up a new code

and it did clear the code previous code was a p1440 i believe and now its gone but two new ones popped up..after 4 days of long drives and also city driving about a tank and half of gas.

This scan tool should be able to tell you EGR pintle position and commanded position....yes i checked it out iam not awesome with the scan tool but it showed me a -14 % ...meaning what??does that mean ecm has to be reflashed have u heard of this?
as for gas cap old one was loose as a lot lizard thats y i changed it i have indeed looked at it and no corosion nor was there and damage to any hose that i could see or find.

[old_master]

Just an FYI on DTC's, how they are stored and cleared.

When DTC's are cleared with a scan tool, a drive cycle must be performed before all monitors can run and complete their tests. http://www.obdii.com/drivecycle.html With practice, it can be done in about 15 minutes and it will force all monitors to run and complete their tests. Each monitor requires a certain set of circumstances, the drive cycle link explains each one. If you don't duplicate it exactly as outlined, the monitor will not complete its test. Usually this is accomplished through normal driving of the vehicle but it can take a while to complete all of the monitors. The SES light will remain off until the monitor has run, completed, and failed its test. It's not uncommon for some monitors to take days, weeks, even months to run, and complete its test, (the drive cycle must be duplicated exactly for each of the monitors to run).

The first thing the inspection station checks is if all monitors have run and completed, commonly known as I/M Readiness, (all monitors are reset each time DTC's are cleared with a scan tool). If I/M Readiness is incomplete, you fail.

Disconnecting the battery may or may not turn the light off depending on what faults are present when the ignition is initially turned to the RUN position. Disconnecting the battery will not clear DTC's from the history file. This must be done with a capable scan tool, not all scan tools can do it.

Hard faults are problems that are found immediately when the ignition is initially turned to the RUN position. The SES light will turn on immediately. Pending faults are faults that the PCM recognized but are programmed to turn on the SES only after a given number of faults. The history file contains faults that are present and faults that may have happened intermittently since the last time the DTC's were cleared. If the PCM doesn't detect the fault after a certain number of drive trips or drive cycles, most history codes will clear themselves.

[bagged98]

k everyone to follow up on this post. i found the problem. i was the purge soliniold. tested the part by hooking up a 100 percent vacuum to it then using the scanner to open the valve from 0 to 100 percent..did noithing half the time then other half drain slow or if you tap the valve it would drain...it was causing the egr valve to malfunction and also was the evap problem 3 weeks no codes no light..

[Tech II]

Don't think it was causing the EGR to malfunction......what it probably did was skew the MAP sensor readings when the EGR was commanded opened.....because the MAP sensor readings were not what they were suppose to be(due to the solenoid failing) when the EGR opened, the EGR was blamed by the PCM....