Photoshopeth

I have an 04 GT auto with 60K miles. I've noticed within the past year the car bucks and shudders really badly when completely letting off the gas pedal after cruising at around town speeds of 25-45. It was getting really bad when I had a cai installed, so I recently threw my factory air box and maf screen back in, cleaned the maf and reset the ecu.

It does it alot less now, but still does it occasionally and when it does it usually shudders just as bad, it runs fine in every other way though. Seems to do it more when it's cold out and seems to go away once the car is fully warmed up, tranny fluid looks to be at the proper level. The car never did this even with a cai the first few years I had it.

Any ideas?

Urambo Tauro

Any codes? Whether or not the CEL is getting lit up, I'd start by checking the spark plugs, and making sure they're not loose.

Phillip123

Rule number one, start with the spark plugs. If their not loose you can move on. How about codes?

Photoshopeth

It's never thrown any codes while I've had it. I've even double checked with my hand held tuner. I thought possibly spark plugs, but it idles really smooth and acceleration never seems to be lacking.

Dave19525

Did you get it figured out? You mentioned you had a handheld tuner, are you running a new tune? Had you changed any setting?

Photoshopeth

I haven't used a tune in about 2 years, the e-mail tuning company could never solve the pinging I had when running the tune. Unless it was tuned by the previous owner, but I doubt it.

It feels transmission related, it shifts a bit firmer naturally because it's a 4r75w compared to my 2000 v6's 4r70w, but it just doesn't feel right when it bucks like that. I'll have to try changing out the plugs, or try getting a transmission fluid change.

WJL

Just out of curiosity who is the tuner that couldn't fix the pinging?

Photoshopeth

PM sent

WJL

Thanks for the info, i have been considering a tuner for a while just haven't pulled the trigger

For $400.00 i want some performance improvements.