Thread: P0203 and P0303 help??

Both those codes are pointing at the exact same cylinder.

You have a cylinder 3 injector issue and a cylinder 3 misfire. So either it's not getting fuel or it's dumping fuel and causing the exhaust smell.

I would swap the cylinder 1 injector with cylinder 3 and see if the misfire follows. Also inspect all the wiring and connectors.

This thread from a different forums describes the same problems.

http://www.automotiveforums.com/t106...warmed_up.html

Codes for misfire and injector on cylinder 3. Check your wiring on that injector.

try a test light, one end to ground, the other inside the plug, the light should flash if the wires are working right.

or you can use a side marker bulb out of the head light, bend the wires back on the bulb and stick it in the plug, it will also flash if the wires are good.

engine needs to be running to see this really, it only flashes for a second when the key is first turned then starts up after its running.

id leave it alone and not look a gift horse in the mouth..........

You should definitely be seeing resistance on the injector. Did you check another? There's not really an exact resistance you are looking for, just want them all close. Loose connector can definitely give you fits. When i first fired up my top swap I had 2 bad injector adapters that made me think my injectors were bad, once I soldered in new connectors my misfires went away.

I guess both. I'd want to do something with the injector with no resistance first. Are you positive you probed the terminals right? Just asking, it would be a quick double check. Then you could pull one injector wire at a time with car running and check the adapter for voltage.

You would think... Electrical problems scare me. Technically an injector is an electronic device, so I suppose they can have intermittent problems as well. Not sure man. Best I can suggest is thoroughly go over all the wires in your engine bay. Look for any breaks in the plastic conduit stuff and make sure wires look good under it. Do as suggested and swap plugs, plug wires, injectors from 3 to 1 or 5 and see what the misfire follows. Do them one at a time. I'd probably start with plug wire, then plug, then injector. If the misfire stays with cyl 3 then you know it has to be the wiring harness or something mechanically with that cylinder.