Ok car is a 90EF 5spd.

Once in a while i'll be driving and my engine light will come on, but it will not hardcode, so i'm guessing its an o2 sensor problem. After the car is warmed up, there won't be a code. I cannot find out which code it is since it will disappear everytime i shut the car off.

Well the car also will hesitate/buck sometimes under throttle as well with no codes showing.

Tonight, the car had a really crappy idle when first started up and an immediate engine light. Car rode like crap the whole way, with twitchy throttle and lots of bucking under light throttle input. Decel even had some bucking.

However, after parking the car for 10 min, and then restarting it, i had Zero problems, no bucking, no code.

So i'm stumped... I plan on checking my plugs, fuel filter, wires, and the cap and rotor. The air element is new, so i pretty much rule out the air part of the equation... has to be either spark or fuel now right?

Any input will be greatly appreciated.

 

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