The check engine light came on do I hooked up a diagnostic meter to the on board computer and it tells me that there is a cylinder misfire #4. So I checked it and i was getting lots of spark. So I reset the computer and go through a drive cycle then the light comes on again! So i hooked the machine up again and it gave me the same code again. So I changed the plugs wires and coils and cleared the code and drove it through the drive cycle again then the light came on again!!!!! What is going on???????

2004 hyundai accent p2096 code (P2096 Post Catalytic Fuel Trim Bank 1 System Too Lean) keeps coming on. it comes on and the car runs perfectly (about 10 minutes after warm up). took it into my mechanics class scanned it with a fancy scanner and there was 2 miss fires on cyl 2 (only on that cyl so not coil cause it is a split coil for cyl 2,4) other than that nothing was out of place. replaced plug wires,plugs,o2 sensors all fluids and filters, deleted the code 2 weeks later comes on again. deleted it took it to air care (Canada BC air emissions test) and went through no problem so the cat is fine. nobody seems to know anything about this. the car is in great mechanical shape besides this and runs really smooth!. the engine light only comes on once and a while no rhyme or reason but comes on less it seems in warm weather?

i have heard that the TSB DME needs an update from the dealer but people have had trouble with this so ill try it and see.

http://www.renntech.org/forums/topic/18073-p2096-post-catalytic-fuel-trim-bank-1-system-too-lean/