fisherm

Hey all. I have a 99 4Runner V6 143k miles that started running rough last week. CEL came on with P0305 (#5 misfire) and P0171 (bank 1 lean). The problem occurs sporadically, P0171 doesn't always show up but P0305 does. When the engine is cold it runs fine. If I'm sitting in traffic for a while or stop at DQ for a blizzard and start it back up it starts running rough. Got a P0304 a few years ago and it was the plug wires so I decided it was probably time to change them again. Changed plugs and wires, but no help. Figured it was a coil pack so I swapped two to see if the problem would move to a different cylinder, also cleaned the MAF while I was at it. Again no help. I've been a lurker around here for a couple of years but never posted anything. But I searched around and found a few guys that had misfire problems and it turned out to be an injector. So I checked the injectors cold, #5 was at 15ohms, same as #1 and #3. So I went to run an errand, it drove fine, got home and thought I might as well check them hot. #5 was at 16ohms same as #1 and #3. So I'm standing in the rain thinking crap now what. I went back to check #5 again and it was at 17ohms, watched it for a while, went to 20, 50, 100 finally 2Mohm. So it looks like I'm going to find an injector tomorrow. Thanks for pointing me in the right direction. Hadn't seen this particular problem posted so hopefully it will help someone out. If it's not the injector I'll be back here tomorrow crying.

Larrymc14

I have literally this exact same problem, bank 1 lean and cylinder 5 misfire. I saw the same other threads too so guess I have to check that injector. Thanks for the info