Oxygen Sensor keeps failing

[mr_picky]

Have an 87 Honda Accord LXI with 279,000 miles on it. Problem is I keep getting a code O1 on the PGMFI. Have replaced 3 times in the past year. The car loses power and gets bad mileage and then the same code comes on. WTF is happening here? Could it be a bad computer or a clogged cat? Any help will be apprecieated.

[mr_picky]

anyone?

[russiankid]

Clogged cat wouldn't cause the sensor to fail. How do you know the sensor fails? Tried testing it?

[Pico]

sure it's not a problem in the harness

[mr_picky]

Why would the pgmfi light stay off for a while and then come on months later if it is a problem in the harness? Yes, I heat tested one of the sensors out of the vehicle and it failed. I took it back and the parts store gave me a new one and now this one threw a code O1. They were Bosch sensors btw.

[2drSE-i]

Any number of things wrong in the harness could cause these problems. Also a bad computer will make the mileage go to shit, and cause intermittent codes. Kinda a hard problem to diagnose honestly, without more information.

[mr_picky]

Checked the old O2 sensor today and it was not bad. Heat tested for two minutes. So what is the first step in checking the wiring harness cause now i think the problem lies there or in the computer.

[mr_picky]

Well now the engine is losing power, smoking, and has a serious oil leak at the back of the engine. Not only that it has oil in the air filter and housing. Not looking good for ol 3 gee. Any suggestions or comments? I think im gonna do a compression check to see if its a blown head gasket, but why would that keep setting off a 01 trouble code?:dunno:

[Lil Mike]

could all that oil be plugging up the o2 sensor making it read really rich? then when you test them it burns off the oil and works agian?

[mykwikcoupe]

swap the 2 connectors for O2-1 and O2-2 leave them both in the same spots on the manifold. See if this clears that code and thows anymore. In my recent case this cleared that ode and allowed the ecu to oss a few sensor codes that wee the real culprit.

The other codes it tossed wee the intake air temp, which just needed leaning and a quick wipe from the oil sitting on it. The Tw sensor was the big one (tan plug on black sensor your reering to in the pics). It caused the engine to run righ which would also foul out the O2 sensors your having issues with. Im not sure why but i was under the impression the ecu would show all codes but mine would only flash one ode at a time till it was cleared andthe battery disconnected fora few seonds. It was a 30 minute hassle but worked out great fo me

[Oldblueaccord]

Its running too rich and ruining the sensor.

If you can record the mileage your getting for a week or if you have a smog station get them to run it and see what your numbers are.


wp

[2oodoor]

Any number of things wrong in the harness could cause these problems. Also a bad computer will make the mileage go to shit, and cause intermittent codes. Kinda a hard problem to diagnose honestly, without more information.

true dat ehh
what is the CO reading on that raschel, what is the actual running temp of the motor, pvc system condition? type of oil? we gots questions:tongue:

[Dr_Snooz]

You want to be sure you aren't touching the sensor surface when you install it. Those sensors don't like finger oil very well. Nor do they like silicone sealer, LocTite, hair gel, etc. I'd also check the condition of the sensor connector. If it's not making good contact, it could definitely make the ECU cranky. Failing that, you might try a different brand of sensor. Bosch stuff is the very best you can buy, when it's made in Germany. The stuff they've outsourced to China is a complete crap shoot. Their oil filters are complete garbage and should be avoided at all costs.

[Discovery]

Have an 87 Honda Accord LXI with 279,000 miles on it. Problem is I keep getting a code O1 on the PGMFI. Have replaced 3 times in the past year. The car loses power and gets bad mileage and then the same code comes on. WTF is happening here? Could it be a bad computer or a clogged cat? Any help will be apprecieated.

Are you adding any addetives to the gas tank, such as injectors cleaners, water removal, ect? if you do, some of them can cause a problem to the oxygen sensor

[alberto]

Well if your blowing withe smoke out the back is you head gasket.blanco