roadstar98

OK, I had the check engine and traq light on. I figured it was the O2 sensors seeing how it has 85,000 miles on it. I drove it like this for a couple of months it ran fine no problems at all. Well I got all four O2 sensors in yesterday and was going to put them in tomorrow. On the way home from work it started missing and smoking real bad I was only about a mile from my home so I made it.

I went ahead and changed all four O2 sensors and this did not fix the problem. The dummy lights are out from me reseting them but I figure they will come back if a drove it. (they are the correct ones and I re-checked my work)

Somthing is causing it to just dump massive amount of fuel in the motor. I had gas comming out both exhaust pipes.

The motor is smooth at at higher RPM but is still rich seeing how it smokes. Its not oil, it smells like straight gasoline.

I put new caps, rotors, plugs and wires on 5000 miles ago and have had no problems.

Any ideas??????

I have a feeling I might have to let Lexus work on this one. I am out of Ideas.

Joe

sonyman

Did you even bother pulling the codes or did you just decide it was the O2's on a whim? It's obviously something much more involved in fuel delivery such as the MAF sensor. Pull the codes!

roadstar98

Yes, I pulled the codes it was 25. (Air-fuel ratio lean malfunction).

sonyman

The next thing I would check would be the MAF in that case. If the MAF fails the engine may run very rich, which is what it sounds like considering you describe a lot of fuel coming from the exhaust.

roadstar98

I did a search on MAF and came up with nothing usfull to me. Is there a test you can do on it with an ohm meter? Do you know of a site to direct me to for some more info?

sonyman

There is a test, but unfortunately I do not have the specifics for your model year. If no one else does, http://techinfo.toyota.com will for a small fee.

roadstar98

Ok, thanks for the help. Maybe someone else will chime in. It's strange It ran like a top with the dummy lights on. I ordered the walker sensors. I was sure it was that but I guess whatever it is it finally petered out today. I never seen so much gas poring out of the exhaust. It was like a steady trickle. Shoot I thought it would catch fire. Anyway thanks for the help.

Warhawk

Remove the MAF and very gently clean the wire(s) that go across the airstream. I've used q-tips and alcohol on other toyotas and it works for a while. If this works you'll know what you need to replace.

Most ECU's go into a "limp home" mode after certain failures, that causes the engine to run rich (to protect from detonation damage).

sonyman

Just to add: In this case, if the MAF were to fail, the engine would have no idea how much air is entering the engine. In order to prevent a lean condition, the engine would have to add as much fuel as possible to compensate for as much air as could possibly enter the engine.

LexLS

I had a very similar problem a couple years ago. I had smoke, almost no power, and the gas seems to flow right through. Unfortunately this was in the middle of winter and so I had to bring it in to a shop. Anyway, it turned out to be a dead ignition coil.

You can do 2 tests for each coil.
With an ohmmeter, measure the resistance between the positive and negative terminals where to wiring harness attaches. The positive terminal is the one next to a piece of plastic that sticks out. Resistance should be 0.41 - 0.50 ohms.

Now measure the resistance between the positive terminal and the terminal where to spark plug wire plugs in. Resistance should be 10.2 - 13.8 Kohms.

If either of these tests are out of spec you need to replace the coil.

roadstar98

Thanks for all your sugestions. I had it towed to Toyota this morning. I will see what they come up with. I will post the outcome. Thanks again.