'03 PT GT NEED HELP WITH DIAGNOSIS!!!

[SILVER03PTGT]

Hey guys,


I am running the intune on my Pt Cruiser with the canned tune. from one driving cycle to the next the tune started over-boosting with a spike between 23-25psi. During that acceleration was very rough and sporadic with back firing and what seemed to be a misfire. I have no codes, since this started i have ran a compression check, everything is good. Injectors are good, coil plugs and wires have been replaced with the gap at .032, no vacuum/boost leaks, solenoids and sensors one by one have been swapped since i have two GT Cruisers. When switching back to stock tune it had similar issues, just on a lesser scale . Went through and tightened any and all hoses and connections. Today the car was running good on stock tune low boost of 14 psi dropping to around 10 at high rpm's. I should note the car was spiking 17-18psi falling to 15 with the canned tune prior to issue. The car was very strong. Mod list is short as i am trying to correct issue. I still have factory exhaust. Cat or oxygen sensors crossed my mind. I have a 3in o2 housing and downpipe and new bosch o2 sensors on the way. 57,000 miles.

msd wires
ngk iridiums
intercooler hard pipes
cold air intake

Thank You
John

[SILVER03PTGT]

I love the tech support! Ridiculous!!!

[ben04srt]

Do you have a wideband o2 to check your afr?

[mikel]

the tune cant change, Id double check the vacuum lines and wastegate actuator.
Also, try resetting the pcm adaptives.