02 Impala Acceleration Degrading

[MCO_Death]

Just had my 03 serviced finally for my acceleration problem. Bat cat's. @ 46k miles. Also doing a full tranny service as it was needed. All service being covered under warrenty at no charge to me. Horray.

To add, I had poor acceleration, horrible gas milage as main symptoms.

[luvmy02impala]

****solved****

*new Catalytic Converter Solved Troubles*

Thanks For All The Help Everyone!

-tom & His 2002 Impala

[1995JimmyLT]

I read about this problem a few times from various onwers and just thought you might like to know, in case you don't know already, although I haven't experienced such a problem ith my 2001 Impala, GM sent me a letter stating that 2001-2002 Impala, Monte Carlo, Grand Prix or Regal owners may have a condition where there is a lack of power/acceleration due to the front endcone insulation from the Cat breaking away and blocking the first catalyst brick, thus preventing exhaust gas free flow.

They state it is not a recall, however, GM is offering additional coverage on the cat if you are experiencing the loss of power issue and are giving 10 year or 190,000 km replacement coverage at no charge! Even if you got it repaired already (before September 15, 2005), you can receive a reimbursement.

I believe you need the letter from them for the deal, but I think that is just awesome! Although, once again, I have not experienced this problem. My Impala just flies beautifully, but it's nice to know that I am covered for a little while and may be something you might like to look into.

[rtx042]

No letter required ...just let them know the symptoms and they will check it out and replace the cat if its plugging up.



\
\

Originally Posted by 1995JimmyLT

I read about this problem a few times from various onwers and just thought you might like to know, in case you don't know already, although I haven't experienced such a problem ith my 2001 Impala, GM sent me a letter stating that 2001-2002 Impala, Monte Carlo, Grand Prix or Regal owners may have a condition where there is a lack of power/acceleration due to the front endcone insulation from the Cat breaking away and blocking the first catalyst brick, thus preventing exhaust gas free flow.

They state it is not a recall, however, GM is offering additional coverage on the cat if you are experiencing the loss of power issue and are giving 10 year or 190,000 km replacement coverage at no charge! Even if you got it repaired already (before September 15, 2005), you can receive a reimbursement.

I believe you need the letter from them for the deal, but I think that is just awesome! Although, once again, I have not experienced this problem. My Impala just flies beautifully, but it's nice to know that I am covered for a little while and may be something you might like to look into.

[duanes67]

My 03 impala had the same hiss and poor acceleration. After analyzing, I finally unplugged the EGR valve. The performance returned. I tried replacing the EGR, but the symptoms returned. So, for now I just run it unplugged.

I'd still like to get to the bottom of the problem, so I guess I'll check the cat converter next. Any other ideas?
Also - there is no 1-2 or 2-3 upshift on wide open throttle (WOT). Have to let up for it to shift.

******UPDATE - Cat replaced and FIXED IT! ******

I took it to a local dealer and the cat was covered by an 8yr/80000mi warrantee. Totally free... Why couldn't I have found this forum sooner?! I already tested/cleaned the EGR, MAF, IAC, and EVAP solenoids; and replaced the PCS, TCC and both shift solenoids. Three OBD II scans missed this one - no DTCs ever showed up. Live and Learn, and search the Automotice Forums!! Thanks guys!

[maxwedge]

Welcome to AF, sounds like a possible cat issue, the unit can be checked with a back pressure gage fitted into a 02 sensor port. It is covered for 8/80k.

[Lexander]

I drive a 02’ LS spots package Impala. I bought the car used in 03’ from a Chevy dealer. The car belonged to a housewife of one of the salesmen there. The car only had 9,000 plus miles on it. Three years later the mileage is at 45,735 miles.

The 1st problem I had with it was the blinkers. They would have a mind of their own and blink on occasion . Found out it’s the relay switch in the dash next to the hazard light button. I remove the dash along with the bad switch then had it replaced and now it works fine.

The 2nd problem I have experienced is shaking of the steering wheel when braking at speeds of 47 – 55mpr. It started shaking after rotating a set of new tires. I went back home and checked the tires again. Then later still not knowing what the problem was I changed the front brakes because it was time. When I changed the brakes I found out that my factory rotors were warped. Now I need to buy a set of rotors!
And I’m not going cheap ! No factory parts 4 me Thank You!!!
(FYI you may have only one rotor that is warped but even so you should change both)

Now my 3rd and so far latest problem with it is the catalytic converter. It went out on me with no signs . It happened quick, from one second zooming up a freeway onramp to the next second totally loosing powe r in acceleration. Every time I would rev the engine a rattling sound would come out from under the car in between the 2 front tires, were the cat converter is located. I found a great exhaust shop that gave me a great deal.
Make sure the cat converter that’s installed is equipped with OBDII electronics.
I also changed the spark plugs, air filter, fuel filter, oil and oil filter.
(FYI if you want to get ripped off, go 2 a dealer! If you want it done right, do your research!!!)

Well that’s my story on my Impala experience. I always count my blessings but this car is just too much so far. I love it but I hate it! I just wish they were made better!

My wife and I have made up our minds and we are going to trade the car in for another jeep.

[Gems]

Originally Posted by maxwedge

Why replace the cat, have it scannned and look for maf readings, o2 readings, and fuel trims these things will tell what is going on, if all checks good, have the cat checked for excess back pressure. Very unusual to replace cats at these mileages. without something causing them to fail.

These cars have known defective CATS... I got a letter from GM (Ive posted a copy of this letter in another thread here) saying because of CAT problems GM has extended the CAT warranty to 10 years or 120,000 miles... I had mine changed by the dealer under this coverage and the car runs like new again...

[richtazz]

Lexander. I agree that going to the dealer for non-warranty service can be expensive (especially brakes and suspension), but paying another shop, regardless of what kind of great deal they give you, for a part that is covered by an extended GM warranty is throwing money away. If your car was still within the warranty coverage, they'd of changed it for free. You can possibly be reimbursed from GM if you have your paperwork, receipts, etc...

[micali]

Its sounds like the CAT. I had similar probs and I had a HI PO CAT put on and it ran better. Sounder better too. It does need a simulator or the check engine light stays on. Chevy will pay you back for any repairs that is done to the CAT. They sent me a letter out of the blue and told me to fax the receipts to them and they would reimurse me and they did.