Brain Teaser - O2 related/Engine Computer

Got the following codes: P0155&P0161 which means Heated O2 heater circuits inop on Bank 2(1+2).

Ok, so I change the O2 sensors on that Bank. No change. Car is missing under a load. Idles fine, cruises fine.

Cant find any vacuum problems or Wiring problems so I took to a shop...they said the same thing.

I think it is a computer but still not sure...any thoughts?

hey i got almost the same thing, but i got 156 and 161.. replaced my sensor but still have the codes.. what do you mean by "missing under a load". I was thinking about having a shop look at it as well, im just afraid that it will cost way more than the problem is really worth.

it is basically missing/backfiring when I give gas while driving. At idle I can give it gas and it wont backfire/miss. I say backfire but it is a mild backfire.

I am going to order a used Engine computer and see if that fixes the problem.

Check your ignition and timing, ignition first. How long has it been since you've done plugs and wires? that could have something to do with it. I'm not sure if your car has a distributor still but if it does change the cap and rotor and make sure its still set correctly. If you have coil packs, just try and test them the best you can.

Thanks for the tips, I went ahead and ordered the used computer. The troubleshooting guide I have says that is the next step.

It is a 1997 and it has had a tune-up in the last 30K

I suppose I will find out real soon.

Did you try resetting the computer at all? This usually needs to be done after doing things like this - or so I'm told.

In case you're wondering, there are a couple of ways to do this. One is by removing the EEC fuse under the hood for about 30 minutes. The other is by disconnecting the negative battery terminal for about the same period of time (haven't tried this one myself).

If I'm wrong, somebody please correct me.

Sure did....I will have the computer Wed..I will post what happens then.

A trip to the dealer is next on the list of the PCM doesnt work

After I replaced the o2 sensor in my car I had autozone read the codes again and I only got po161. So i had gotten rid of one code (PO156), then I had him reset the engine codes so it was blank again, then I went back 2 days later and there were the codes again 156 and 161.

how much was the computer you ordered?

85$.

PCM didnt fix it. I changed out the #2 and #3 spark plugs and the car runs great again. I still have a hard light of P0155 but I dont care because the car is running great. I should have justed changed the plugs in the first place. I went from a champion plug that I had put in the car about 15K miles ago to a motorcraft(ford) plug. Something fouled those two plugs but it I am not sure what. Just glad to have her running good again

I now have a california emissions PCM for sale.
michael.redmon@us.army.mil

85$ Works

try a better scanner like obd2

same prob here code 155+161 already replaced o2 sensors,checked connectors still comes back any ideas.