Transmission or sensor?

2002 Chevy Impala 3.8

I have notice if I'm at a stop and get on the gas kind of hard (Not to the floor) that the car will not change gears :confuse: If I don't get on it hard it will shift fine. I had the Transmission Filter changed Saturday and still does it. I was wondering if there is a sensor I need to be looking at? Or do I have a Major transmission problem getting ready to strat?

When the car shifts gears it is a smooth shift like always.. Just will not shift if I get on it, I have to let of the gas to let it shift? Any thoughts?

No check engine lights are listed.

2002 Chevy Impala 3.8

I have notice if I'm at a stop and get on the gas kind of hard (Not to the floor) that the car will not change gears :confuse: If I don't get on it hard it will shift fine. I had the Transmission Filter changed Saturday and still does it. I was wondering if there is a sensor I need to be looking at? Or do I have a Major transmission problem getting ready to strat?

When the car shifts gears it is a smooth shift like always.. Just will not shift if I get on it, I have to let of the gas to let it shift? Any thoughts?

No check engine lights are listed.


if you try to accelerate from stop quickly the car does not move and only rev's your transmission is shot..........

No the car goes.. To about 35 mph - 3000-3500 rpm and stays there for 4-5 sec's before it shifts or I have to let off the gas and push it back down, and it runs fine.

Note: This is only if I get on the gas hard (ie. trying to get the car from 0 - 55 quickly, but I don't have it to the floor either.) If i take off slow it has no problems shifting..

No the car goes.. To about 35 mph - 3000-3500 rpm and stays there for 4-5 sec's before it shifts or I have to let off the gas and push it back down, and it runs fine.

Note: This is only if I get on the gas hard (ie. trying to get the car from 0 - 55 quickly, but I don't have it to the floor either.) If i take off slow it has no problems shifting..

normally if your gas pedal is depressed 3/4 or more transmission will not upshift. so when accelerating to 3k-4.5k rpm let up off pedal half way then slowly push down this will give good increase in speed.do not let up all the way and hammer the pedal again as this is baddd for tranny.........

Okay after leaving Work last night. I was making a hard left and the car sounded like I hit something, and was dragging it, till I straighten out the wheel. It did it 3 times after that and I have checked and there is nothing under there?

It is only on Hard Left hand turns.

Could it be the CV Joint and would that have anything to do with my Transmission issues as well? My wife said it happen to her about 2 weeks ago when the Transmission also started giving us problems.

Okay after leaving Work last night. I was making a hard left and the car sounded like I hit something, and was dragging it, till I straighten out the wheel. It did it 3 times after that and I have checked and there is nothing under there?

It is only on Hard Left hand turns.

Could it be the CV Joint and would that have anything to do with my Transmission issues as well? My wife said it happen to her about 2 weeks ago when the Transmission also started giving us problems.


cv joints when starting to go will make poping noise and this is transmitted into the steering wheel at low speeds . check rubber boots for tears and grease coming out at cv . if so cv n/g. also if you like to accelerate quickly from stop with wheels turned this will kill you cv joints fast....................very fast.

That would make since.. The Turn I have to turn when leaving my house is from a stop to hwy. Some times in order to go you have to go and get on it.

Could this be causing the issue with my tranny?

could be your CAT failing. GM extended the warranty because of problems. If the cat plugs you have to use more "power" to try and over come the backed up exhaust gases which inturn make the transmission shift later. Do you have any stored DTC's not all of them will turn the SES light on.

We have to have emisions test done every 2 years, and I just passed Last Saturday.

Definately sounds like the CAT to me as well. I had the same issue and Chevy did fix the problem. Thank goodness because it definately was a pricey repair!

could be your CAT failing. GM extended the warranty because of problems. If the cat plugs you have to use more "power" to try and over come the backed up exhaust gases which inturn make the transmission shift later. Do you have any stored DTC's not all of them will turn the SES light on. Taking the Car in to have CAT looked at.. After seeing your post I have been reading up on what other problems people have been having.. everything seems to make since. I would have thought for sure with the CAT messing up, it would have caused me to fail the Emmisions test 2 weeks ago, but I have been told since then that is not always the case.

I noticed this when trying to take off fast, and thought it was the Tranny. But I have been complaining about the loss of power for about 8 months.

Good Luck and keep us posted! In my CAT they found metal particles that had completely clogged the CAT. We started losing power about a year ago and it progressively got worse to the point we could barely move the vehicle. I swore it was the tranny.

What is the metal particles from? Is that going to cause me more problems later?

Yeah at first I thought it was the tranny too, but then noticed I have some issues when in park. It is hard to get the car to hit 4000 RPM, and when it does the engine sounds awful, makes a clattering sound.. Not like the Rev limiter. One of the thing I cannot figure out is I'm getting fuel either from my back middle injector or from the Return fuel line right above that. I'm hoping that is caused by the back pressure to the engine from the CAT.

I was told the metal particles are actually breaking off the CAT and then clogging up. I am not a mechanic nor am I good with cars, just going by what my mechanic stated. Chevy did confirm it and I was told it would be an issue later on because they fixed the problem.

It is also idling lower when in Park then Jumps from 800 RPM's to 600 then right back to 800 RPM's.. It use to Idle around 900-1000.

Chevy did confirm it and I was told it would be an issue later on because they fixed the problem.

Would be?

It is also idling lower when in Park then Jumps from 800 RPM's to 600 then right back to 800 RPM's.. It use to Idle around 900-1000.

you need a repair shop to checkout your vehicle, as you have many issues. find an honest highly recommended auto repair shop and have them inspect and give solid repair quotes..........

you need a repair shop to checkout your vehicle, as you have many issues. find an honest highly recommended auto repair shop and have them inspect and give solid repair quotes.......... I just got back.. I was told before I even think about fixing the CAT I need to have my lower intake fix. I'm leaking oil/antifreeze. He said if there is something wrong with the CAT and I fix it now, that this one will probably go out again with that leaking. Does that sound like an Honest reply? He cave me a cost of $700 to have the Lower intake Gasket replaced?

I just got back.. I was told before I even think about fixing the CAT I need to have my lower intake fix. I'm leaking oil/antifreeze. He said if there is something wrong with the CAT and I fix it now, that this one will probably go out again with that leaking. Does that sound like an Honest reply? He cave me a cost of $700 to have the Lower intake Gasket replaced?

i'm very confused as now , you are taking manifold leaks. so let's see cv joints, cat, transmission, manifold.this is adding up to a large amount of money.....If the dealership stated your manifold is leaking and you have found no loss of fluid i would go to another repair shop for this inspection and quote on repair issues and costs.....

CV joints - are fine I found out what the problem was there. That was nothing. When they Changed the Oil the moved the plastic piece to get to the oil filter and the tire was rubbing it.. Got lucky on that one.

Transmission - is fine, no Problems there.

CAT - I think is still clogged.

Lower Intake Gasket - I can see is leaking.. I don't know how we missed it in the past. I do have a small drip in the Garage but nothing really worth writing home about. I usually only have to add a quart of oil if I go 6000 miles between Oil Changes. So is the Leak causing as much issues as what they said I really don't know. I do plan on having someone else look at it. To me if the gasket is leaking on the lower intake, it would be saver to Fix than not. I got another price from a local in my area that does do great work for $550. But he agrees that, it still sounds like the CAT is clogged.

Had the CAT replaced yesterday and everything is back to normal.. Now I'm just hoping this did not cause othere problems that will come up later.

Did GM do it for free?

Had the CAT replaced yesterday and everything is back to normal.. Now I'm just hoping this did not cause othere problems that will come up later.


the cat that came with you car and all the other impala's were defective. if everything is operating normal now you should be fine . your oil leak is small and because of the cost just keep an eye on it. if it were antifreeze , that is serious, and would require repair........

Would be?

Sorry! I meant wouldnt be an issue in the future!