2002 Impala shift problem....help!

Cleveland, TN

#81 Jun 18, 2008
2003 Imapala LS with a 3.8 engine. 98,000 miles which most are all highway miles. Out of no where car started to hiss upon acceleration and loss of power. Gas was being wasted like crazy. My husband sprayed ether around the intake and the engine stalled. Removed intake manifold (plenum) found a hole right on top where it looks as if someone held a torch to it until the hole appeared.

Did tune up and wires kept falling apart. Thought we bought bogus wires, returned them and tried again. Same issue.

Changed wires again last night and fuel filter. Car died...would not start! Found out battery was dead. So we used a friend's battery, started the car up and it idled high...hit the road, heard a load pop and the car ran like brand new. Got it home and lifted the hood...the CAT was flame red. Freakin CAT was heating up so much it was melting my wires, and caused the hole in the intake.

Unfortunatly, the dealer only covers the warranty on the '01 and '02 Impalas, so now I am stuck replacing the CAT.

Also had ignition issued with only 40,000 miles. The tumbler fell apart on the inside.

Great cars, but poorly made. And due to the economy, even though GM knows they have extreme issues in these vehicles, they will not have a recall!

My advice to all, is if you have issues with acceleration that clears up when you floor it...check the CAT ASAP before it melts some of your other components as well!

Vacaville, CA

#82 Jun 24, 2008
I had that problem too. Its your wheel hubs and it cost me $3500 to have all four replaced with new pads and rotors all they way around.

Vacaville, CA

#83 Jun 24, 2008
Check your Cv chafts. thats what was causing my shaking front end

Guntersville, AL

#84 Jun 25, 2008
chris wrote:
I have a 2002 LS and keep getting a P440 code. Emissions leak. I'm going to try the gas cap as it is the cheapest part to replace. It doesnt look like it is leaking though... Anyone ever find a vacuum leak anywhere else?
make sure to click your gas cap 3 clicks past tight when you are putting the cap back on, this is the most common couse.
c johnson

Conway, AR

#85 Jun 27, 2008
i have a 2002 impala and i've had almost every problem u guys r talking bout. ive replaced my catalyic converter twice. and just recently my transmission started to shift hard, took it to the dealership and was told i needed a new tranny, had it replaced and i'm still having the same problem. along with that now my traction control service light keeps coming on and the traction keeps activating on dry pavement. somebody please tell me whats wrong b4 i spend another dollar

Nampa, ID

#86 Aug 1, 2008
Its your catalytic converter. My 2002 was doin the same thing. It even made a whistlin noise after a while. I got it replaced and runs real smooth now.
2003 impala


#87 Sep 13, 2008
Jim wrote:
I recieved a letter from GM just after I bought my 2001 Impala LS that the catalytic converter may be faulty, and they will replace it if it goes bad, up to 200000 kms.
I replaced my catalytic converter on my 2003 Impala LS in MAY 2007. Brampton GM mechanic said the cat converter was plugged causing high back pressure. This caused poor acceleration of the car. I originally thought the problem might be spark plug or fuel filter related, but it was not the issue. The new catalytic converter solved the problem and repaired under GM warranty of 130,000 KM, saved me $758.
Back in July 2006, I had the O2 sensor replaced and the GM mechanic said that the PCM had to be reprogrammed as well. Car ran fine after the work was completed.
I've heard that O2 sensor problems can lead to plugged up catalytic converter problems.
Does this seem to be a common issue with GM vehicles?
I am suspicious about the O2 sensor working correctly, since the cat converter plugged up almost a year later.

Danville, VA

#88 Oct 1, 2008
I don't know if you still have this problem. I was having similar issues with my 2000 Impala LS. 3.8 V6. After a bit my tranny would start shifting roughly. Sometimes i would shut car off, and restart and would be fine. I put new spark plugs in and fixed problem. Tranny shifts great at all times, and engine runs fine. I just passed 177777 miles. I changed plugs about 3 months ago, or at 167000 miles, and haven't had the tranny shift poorly since. Spark plugs are generally the cheapest way to go if having engine problems. It definately fixed mine.
DW- Bronx-NY wrote:
Hello, I have a 2000 Impala LS 3.8 VL. It was brought from a private owner at 40,000 miles. It was having problems accelerating by 60,000 miles. Got it checked out and got multiple tranny codes, p1811, p1860. Wanted $1600 to fix, No way!. Ended up buying a tranny from a junkyard, taking a chance, got it checked out afterwards and got the same codes along with engine misfiring code p0300, p0730 for problems shifting.. The vehicle is currently shaking as result of misfire and i don't even know if my tranny is good. Is it possible the computer codes have to be reset as far as the transmission? And how can i stop an engine misfire at low cost to me. Somebody, please provide some insight on a possible solution. This car has other problems, but I'll be here all day. Help!

Danville, VA

#89 Oct 1, 2008
It seems that the quality of the Impala declined in newer years. I have a 2000 impala. I bought in 2003 with 62000 miles on it. I just passed 177777 miles. The only thing i have done to this car was changed front wheel bearings, front axles a year ago (car was shaking from front end badly, started with shaking during acceleration in right turn, but became all time), and then just routine oil changes, brake pads, and that's about it. I haven't had any problems otherwise. I will tell you that I am currently testing with HHO, hydroxy gas. I haven't shown any increase in MPG yet, but with the gas, it feels as though i have more power, and shortly after running with HHO, my check engine light went off and has stayed off! I am doing tests to try and increase MPG. for more info check out you tube, just search HHO and you will get a bunch of videos. also, hhohuntsville.com and ho4free.com are good sites with good information. Part of the HHO gas running through is it removes carbon deposits from engine and exhaust because it basically steam cleans while it burns. the emissions from HHO is H2O, in gas form (steam.) For those with cat problems with it getting backed up, this will probably fix the problem and prevent it from happening in the future. Emissions are virtually reduced to 0, and supposedly there is a tax break you get because you are making your car a green car. does not void any warranties. you just pump the gas into air intake.

Brooklyn, NY

#90 Oct 30, 2008
Sean wrote:
Glad to know its not just mine!! I'm at 115,500 and I have pretty much the same problem only with a bit of shaking in the acceleration process. That catalitic converter sounds like that may be about right. Also does anyone know why a low tire pressure light would come on even though the tires are all at an even pressure??
do you know how to reset the oil life? if so, then you have your answer look in your owners manual.

Catawissa, PA

#91 Nov 1, 2008
chris wrote:
I have a 2002 LS and keep getting a P440 code. Emissions leak. I'm going to try the gas cap as it is the cheapest part to replace. It doesnt look like it is leaking though... Anyone ever find a vacuum leak anywhere else?
440 is a large leak. If you don't have axcess to a smoke machine ,cig. or cigar smoke will work.
Introduce at the test port underhood.
Look at the canister inside the drivers rear wheelwell,common spot

Since: Nov 08

Boston, MA

#92 Nov 1, 2008
Dee wrote:
I know the problem the catalic converter gets stopped up go to the nearest muffler shop and tell them to check the converter . I had mine removed and now its jettin I even won a couple of races!
I also had a problem with shifting on my 2001 impala at 80,000 miles and i thought the tranny was junk.It turned out it was the cat converter and the tranny is still fine at 225,000 miles. My son now drives it and i drive a 2005 impala LS.

Port Dover, Canada

#93 Nov 24, 2008
i have a 2002 impala 3.8 ls. have no acceleration. did all testing like clogged converter,fuel system test,changed fuel filter.it has 280km.i do not know what to check next.any help
pissed off in pa

Warren, PA

#94 Mar 13, 2009
its your cat converter
sappy wrote:
When I attempt to pass and my car shifts to a lower gear, it gets "stuck" at 4500 RPM and will not shift back into the higher gear until I let off of the gas for a second then continue to accelerate slowly. Itís a pain when passing, or getting on the highway. Just had tune-up and didnít resolve issue. If I drive slow constantly, the car drives great and shifts fine even up to 80mph if I get there slowly.
Any help is appreciated!!!
pissed off in pa

Warren, PA

#95 Mar 13, 2009
look up the information people its there for the takin gm has a special policy # 05551 for 01 impalas for just this problem the converters are plugging up and cause all the problems you and i are having i am fighting with the dealers now only inteligence and persitsance will prevail so do your homework

Mesa, AZ

#96 Mar 31, 2009
I had the same problem and it was catalic converter.I put a new one my car run like new.

Olympia, WA

#97 Jun 12, 2009
Our 02 Impala is doing the same thing -- ramping up to get it to 20 mph -- don't even think of using it on the hwy for fear of getting run off the road. It's scary enough just driving through town because any stop and take off is questionable as whether the car will move. Also, noticed when you turn corners it loses all power too. Very frustrating. Check Engine lights been on 3 times and a sensor has been replaced three times. Starts getting expensive! Any relief or help to solve the same problems you have also all talked about would be fantastic. The last auto shop checked our catalatic converter and said it was great -- so I'm not convinced it's that for us.

Laconia, NH

#98 Jun 19, 2009
my 2001 impala sometimes wont engage into gears(any)...yet sometimes engages fine..this happens within minutes of engaging just fine..without even turning off engine...shifter freely moves yet tranny wont engage PLEASE HELP!!! im laid off and broke cant offord mech. to explore problem
Technician R

Westerville, OH

#99 Jun 19, 2009
jodi wrote:
my 2001 impala sometimes wont engage into gears(any)...yet sometimes engages fine..this happens within minutes of engaging just fine..without even turning off engine...shifter freely moves yet tranny wont engage PLEASE HELP!!! im laid off and broke cant offord mech. to explore problem
The most important basic check would be to make sure that the fluid level of the transmission is correct. A low fluid level can cause the symptoms you describe. Follow your owners manual instructions on how to check the transmission fluid level and add fluid of the correct type if needed. Repost your results. How many miles is on this vehicle and have you ever had the fluid changed? Is the transmission making any abnormal noises before or after this occurs?

Laconia, NH

#100 Jun 20, 2009
there is a sound which resembles a vaccume leak, however gm dealership told me tranny doesnt have any "vacume" type parts and is hydraulic...he suspected either fluid is low or overfilled...or possibly the shifter cable is worn...my hubby is checking it today..car has 230,000 miles...has always been reliable until now....

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