Operation Lipstick on a Pig

[olds307 and 403]

Grab the P code, how many O2 sensors are on it. I changed the temp sensor on this Tercel, there is two, one for the gauge and one for the ECM. Still getting the code, I am trying another sensor, don't want to go any further. Older EFI vehicles, custom flashes included can have wonky issues. At least OBD 2 cars are sensitive enough to actually leave codes, the older OBD 1 had to run horrible for a long time to leave a code.

 

[fleming442]

There is just one on each bank in the manifolds; the post cat one was omitted (along with the cat) and set to "no report" in the 'puter. For some reason, it doesn't like to stay in no report mode.
All this being said, I haven't had a chance to drive it- have to wait for my country roads to melt off. It may straighten out with some drive time now that I cleaned the fuel filter.

 

[fleming442]

I finally drove it with the new muffler, and yes, it's still too damned loud- 3" resonator time. In other news, the CEL came back on halfway through the commute. I had stopped at a 7-11 15 minutes in and noticed a pronounced miss when I left; it seemed to clear up, but then the light popped on. Then, my gas mileage went to sh*t!!! Ugh, diagnosis time.... I popped the hood when I got to work, and the plug wire didn't burn on the exhaust, so that's out. It looks like it may still be the original coil pack, so that's suspect. And, if the lean code is back, I guess I could have a bad injector.

 

[TURNA]

Did you ever change the ICM?

 

[fleming442]

Yah. The ICM, wires, and plugs all have 20k miles on them. One or 2 of the coil packs have been replaced prior to me getting it (only one has cyl #s printed on it).

 

[DRIVEN]

It's just tired from all the winning.

 

[TURNA]

You replaced the ICM or you got it with a replaced ICM?

 

[fleming442]

I put it in, and fixed it's lack of ground when I was chasing the VATS problem.

 

[TURNA]

https://easyautodiagnostics.com/gm/3.8L/ignition-module-and-crank-sensor-test-1

 

[fleming442]

So, I was all set to figure this thing out and it fixed itself. I had about a half can of SeaFoam in about 4 gallons of gas when it tripped the CEL this morning. It got horrible mpg and forced me to get enough expensive gas to get to cheap gas. Stopped a few times for errands, filled it up, and the blasted light went out. So, I mashed the gas 4,5,6 times on the way home to blow it out. Came home, left it idle for 5-10 minutes, and it's been good. See what happens tomorrow.