I own an 05 corolla sportivo with a CES cold air intake with a K&N pod filter, CES headers and custom exhaust. At one point in time the previous owner had played around with the PFC and had some success with it but enevitably returned it to stock. I bought this car second hand in November of 2011 and havent had any issues with it until now. I have been having a lot of issues with idle for about a month now. One day just pulled off a set of lights (not hard at all, bit of granny driving), and i noticed a lack of power i then put foot back onto clutch revved the engine a little then released clutch and all was good for about two days. Then car started to spit and would not hold a steady idle was ranging from 500 to 2000 and so i let it go to see what would happen and then it went down to 500RPM and then just stalled. I started car and it was all good for about an hour or so but when i was driving and released the accelerator a little you would hear a bang from the exhaust pipe kinda like a back fire. I looked on these forums and i found that majority of the causes are dirty MAF sensor, dirty ISCV and also that the pod filter having too much oil would cause this. I didnt do the last service on the pod filter but seeing as it has been almost 7 months of me owning the car and no issues i kinda had my doubts about it. Anyway i cleaned the MAF sensor as that is what everyone had said was the main culprit and it seemed to work for about a week until car wanted to stall again. So then i went and cleaned it again along witht he ISCV and the air filter and also changed the oil and oil filter just incase there was dirty oil coming in from the intake. The oil had been in car for about 5000-7500kms and car had been fairly thrashed yet oil still looked good. Anyway after cleaning all of these using the step by step for cleanign ISCV the car worked fine for about a week again until it happened again. So starting to get frustrated i took it to a toyota service and parts and had it looked over. What they found was that the piping had been moved and no coolant was going to the ISCV so they reconnected it the way it "should" be and also replaced a gasket in the ISCV. (Previous owner had bypassed throttle body in an attempt to keep the air entering engine as cool as possible). Again car worked fine for a week or two until it wanted to stall again and i had to drive around with one foot on clutch one on acclerator and hand on the hand brake. I took it back to the service and parts and he said he would have another look so he cleaned the ISCV again and did all the checks and said it was working fine. It did work fine for the rest of that day and then it happened again. I havent tried anything since and that was done friday just gone. It only ever seems to happen when engine is warm. I tried the other day hitting lift when i had the issue and it seemed to resolve the issue so next time it happened i hit lift again but this time no success. I have no idea what else to do and i dont want to hand money over to the dealer if they dont know what is happeneing either. This is my second car and is my first car with mods. Im hoping in future to learn more to add more mods but wish to solve this issue first. I have talked to a few people and they have given me advice to check coil pack, the earthing wires and that prehaps in an unlikely case it could be an O2 sensor. I havent checked the earthing wires yet as i havent had time but was wondering if anyone else has had same kind of issue and has resolved it. Any help would be appreciated. Sorry for massive post Sam