So i get a p0303 when i start my car, and when the rmp's are around 1500-2400 while driving. i have replaced plugs, wires, #3 fuel injector, all with OE parts. i have completly cleaned the EGR, EGR manifold, and the VSV switch and all vaccum lines. and tested the secondary resistance of the coil packs for cold and hot(their with in specs). iv also tested MAF sensor, iacv, coolant temp sensor, and everyother sensor associated with the P0303 code. after all this the "chug-chug" at stops while in drive or reverse has almost been completely fixed, i still get the code. what should i check next?
another p0303 question. on 1999 Toyota Camry
Did you get the code cleared? If not, get it cleared and try again. Sounds like you checked all the right things but you didn't say you cleared the code. Next thing I might do is, using an oscilloscope, check the waveforms at the coils and injectors. That may tell you something. You may also want to change fuel brands and maybe the fuel filter. Just a guess but you've checked a lot. Also look for corrosion or water in the injector and coil connectors.
i do have a pocket scanner and clear the codes after i do anything. ill try the fuel filter next i suppose. all the connectors for fuel injectors and coils are clean and clear. i was wondering, could a burn valve be a result from a P0303? i bought the car and was fully aware or the idling issue, but if the old owners just left the problem alone and just kept driving it, is it possible they burnt the valve? maby the fuel injector was the initial problem, but now now iv replaced it and its still getting the P0303? also could driving it and running premium only, and some eninge cleaner help a burnt valve? thanks.