Misfire problem

[RobertSS]

HI @ All

when the car is cold its drive and accelerate ,all is normal,but when its got warm i can only put my foot softly on the gas,otherwise it pops,shakes and dies..in every gear ..but i can start it normal and it idels fine ,if its in neutral i can go WOT without any problem.....when i go in any gear it beginns to pop,when i put down a little,little more gas.....i change the fuel filter.....nothing....any ideas ? coil ? why its only when the motor is warm ?
engine have 80k miles
Car is a 2001 SS

thanks all maybe you can help me

greets from vienna

Robert

[SMWS6TA]

any codes pop up?

Sounds like your Cat is clogged.

[JayTA98]

any codes pop up?

Sounds like your Cat is clogged.

agree. Do you have a SES light on? We need some more info. When was the last time you cleaned the MAF? did your plugs, etc

[RobertSS]

the maf looks clean......plugs....mhhh they can be bad,only under heat ?

thanks for the cat maybe another idea ?

yes SES light is ON but i have no tool .....so its expensive here in austria to read it out .....but at the end i have to do it

[SMWS6TA]

when you get the codes post and we can try to help more.

Based on your mileage and description of problem I'm going to stick to Cats being clogged until I see a code

[JayTA98]

the maf looks clean......plugs....mhhh they can be bad,only under heat ?

thanks for the cat maybe another idea ?

yes SES light is ON but i have no tool .....so its expensive here in austria to read it out .....but at the end i have to do it

yeah unfortunally is hard to troubleshoot without reading the codes. How much they charge for reading it? If it is too expensive look into getting a scanner yourself. its very handy to have one.

[0rion]

what is your temp gauge doing? Does it show it coming up to temp? A bad coolant temp sensor will do what you're describing. Car will run fine in open loop but as soon as it goes to closed loop it'll over fuel. Normally it'll overfuel so much it won't even idle though.

After that I would check fuel pressure ( 58psi).
If the fueling side checks out I'd look at a burned or cracked plug wire.

[RobertSS]

Hi ! Thanks to all .......codes shows Cats and O2......tomorow get new cats,clean the o2 and hope all will be fine ......greets Robert

[JayTA98]

Hi ! Thanks to all .......codes shows Cats and O2......tomorow get new cats,clean the o2 and hope all will be fine ......greets Robert

make sure you replace the correct sensors. You have 2 pre cat sensors and 2 after the cats. If the codes are for the pre cats then you might not need to replace cats. If it is the after ones after the cat then i will suggest to swap them with the front ones. If codes remain the same for the after cat one(even with swap) then most likely your cats are bad and need replacement.

If the code follows to the pre cats(after you swap them) then you have 2 bad O2 sensors.

Can you post the codes? I dont think cleaning them is going to help out so much.

[RobertSS]

Hi ! i dont know what o2 the codes show....will look today .....you think it could be only the o2s ? ......but i will do it and let you know .......thanks for your proffesional help .....!!