- This topic has 28 replies, 5 voices, and was last updated 11 years, 3 months ago by .
-
Topic
-
Hello ladies and gents,
New to the site but a HUGE fan of youtube videos from ETCG. Here’s my problem:
I have a 2000 Toyota Corolla LE, standard shift, 121,000 miles. About 2 weeks ago, all was fine as I was driving, but then noticed a sluggish response when I stepped on the pedal. The CEL started flashing for a minute, then stayed on steady. I went to autozone and had it checked with the OBD tester. It showed code P0304-misfire cylinder 4, along with an O2 sensor as a secondary code.
I bought and installed 4 new iridium plugs and reset the CEL and the car ran much better….for about a half day. The misfire started again but no CEL this time. Well, I figured that the coil packs should probably be replaced also, so I did this too. I replaced all 4. Started it up and the idle sounded strong…I thought this was the fix. Took the car for a 20-mile test drive and ran it hard. It ran GREAT!!!! At the end of the test drive, I pulled into my driveway and it started the misfire again, but not as bad as before.
I pulled the plugs and the threads were pretty darn wet with what I believe is oil. It didn’t smell like gas so I ruled that out. Before I start changing every part that I’ve seen that “COULD” cause a misfire, I figured I’d run it through this forum first.
A few other things that may or may not be important:
-the car kicks out a nice poof of smoke from the tailpipe during a misfire.
-misfire seems stronger after having gone down a steep hill, stopped at a stop sign, and then accelerating from the stop sign. (not while stopped at the sign, just after leaving the stop)
-when in neutral and at idle, when I push the pedal (or the throttle cable), it sounds like the engine takes a quick “Gasp” of air before the RPM increases.
-Still excellent fuel economy—36/gal combined on average (I edited this post to include this information, since you’ll see an entry mentioning this by me below)I’ve seen things suggesting the IAC, MAF, PCV, etc. etc. I have not replaced or cleaned any of those yet. I guess I could, but I’m thinking something is going on right after replacing the plugs and wires. The car runs great immediately after the change, but then it goes back to its shenanigans.
Should there be oil anywhere on the plug? Or is it supposed to be on the threads? If not, should I replace the valve cover gasket that has the spark plug gaskets included?
I’m at a loss and I appreciated any and all suggestions. I’m trying to be a DIY mechanic like ETCG says we can all be (to an extent). I really, really want to fix this myself so I can say that I did it (with some help from here, of course)
Thanks in advance.
- You must be logged in to reply to this topic.