Hello,

I have a 2001 monte SS 3800 series II.
I've personally replaced the cat converter 3 times myself. 4th time i went to the dealership, they put it on and reprogramed the computer, then they went out of business.

I am not paying for another cat converter that dies in 18 months. I need to either get a computer mod of sorts, or a sensor that fakes the code. I've seen emulator o2 sensors, but i'm not sure that'll do it.

I'm not sure what the deal is with this car but it destroys cat converters 18 months or less.

I can't afford number 5. Number 3 was a magnaflow no U bend, i'm going to toss that back on, even though it won't pass emissions.

Please forum help me out on this. I do not care if it's illegal just need the thing to pass. I've wiped the computer codes, I was told if i get it after the first failure but before the 2nd i can still pass. I just assume end this forever and get something to shut the computer up for good.

I have SLP cat back exhaust, not sure if that's what destroys the cats or not, should'nt as slp was supposed to be chevy proper somehow?

My sticker is up in july, it's july, please help.

 

P0440 is an EVAP code.
P0420 is your Cat code.

You don't have a Cat problem if you are seeing the P0440 code. You have a problem with your Evap system. Could be something simple like a bad gas cap, could be something like a damaged hose in the whole system or near the purge solenoid. Could be a clogged line.

Also your first cat should have been free, there was an extended TSB on the 2001/2002 cats where they would replace the faulty cats.

 

it's not the gas cap.
It's been fixed by chevy for p0440 it was the cat. Don't ask me how.

Is it possible the idiot who replaced my fuel pump didn't seal things? Although not sure how it would go away once they changed the cat. The car is a lemon, always has been, alternator and engine are the only parts that haven't been replaced at least once w 150k

This issue has been on off since 50k or so.

How do i hack the comp? or where can i get the comp reprogrammed to just stop crying?

 

P0440 is just simply the EVAP system. There are NUMEROUS things in the EVAP that could be wrong. Could be something simple. Another Cat won't help you.

If you really want you could do an EVAP delete on your car, or you could just throw all real mechanical abilities away and just cover up the code with a PCM from ZZP with the P0420 delete, EVAP, and EGR deletes (under option 4)

But I'm telling you, it's not the Cat.

http://zzperformance.com/grand_prix/...=182&catid=107

 

i'll bite, it's not the cat ok. that's why i'm here. also makes sense why the dealership disappeared...

So evap system, is there a thread on what that entails aside from "i need a new gas cap" sounds like there could be a pin hole anywhere in the non pressurized portion of the fuel system? pre pump? general gas tank area?

The new pcm sounds like it'd do fine, but i don't neccesarily want all the destroy your engine efficiently codes.

and the transmission torque protector disable? here's a simple way to that end. get the car up to the govenor speed of 107, then throw it in reverse. save yourself the time... plastic gears in those transmissions.

anyway evap thread? anyone selling a haynes manual for the 01? i have one but it's all for the old body style, which makes all the diagrams a tad wrong.

 

If you can find the service shop manuals, perhaps those will help you much more than the haynes manual. I have a set for my 2000, it's 3 HUGE books, everything you could possibly want is in there.

The GAS CAP code!!!!!!!!!!!!!! - Automotive Forums .com Car Chat

^That's a good thread on another forum about all the EVAP codes.

I believe you need a Tech2 to scan the EVAP system to find out where it is failing, or else you are just going to be blindly replacing hoses.

Here is a link for the service manuals on ebay, though this one is really expensive it gives you an idea of the 3 books I'm talking about:

http://cgi.ebay.com/ebaymotors/2001-...e#ht_500wt_803

I got my set for $20+shipping

 

I suspect when the dealer/shop changed the cat they cleared the codes and it was just a matter of time until they popped again.

I don't recall which evap code I chased on a friend's '97 Grand Prix (same 3800 v6), but when I looked it up it was recommending we check vacuum lines. Luckily, these cars don't have a lot of lines to check. On his car, I found a couple rubber couplings connecting to hard plastic lines that looked questionable. I managed to "improvise" by replacing them with 1" pieces of rubber vacuum line I had laying in the garage from another project. Cleared the codes with a Snap-On scanner and last I heard from him the light has not come back on (personally, I feel I got lucky on that one).

My wife's Mustang had a evap code only to find pin holes on the filler neck between the cap and the tank. I was not inclined to want to spend $150 for a replacement neck. A light debris clean up and JB Weld, paint, and I didn't need to clear the code, the car was kind enough to deactivate the light after a day of driving.

Chibi's right, get your hands on a manual for the car, it might save some serious headaches.

I would start by checking vacuum lines and also make sure you have no fuel or fuel vapor leaks (odds are if you are leaking fuel or fuel vapors, you will smell it).