I have a 2002 F150 4x4 with 5.4, the check engine light came on and I scanned it with a P0155 and p1152, I bought a o2 sensor from Carquest as the nearest Ford dealer is 165 miles away, I live in the big bend area of Texas, it was a bosch unit #75-1651, when I unpluged the harness, one of the pins inside the connector was corroded off, I soldered a jumper wire to get around the bad pin, I did disconnect the battery, before doing any work, when I got the sensor in, and reconnected everything, the code was erased and did not come back, but now it has a miss on acceleration, it idles fine but when you are cruising or accelerating, it bucks and misses, any suggestions, we do not have a mechanic here except for myself, and I am stumped.
Please help me.
Thanks in advance
David

 

Hi David and welcome to FTE

Just replacing the O2 shouldn't cause a miss, even if it was the wrong one or something.
Could it just be coincidence that it started then? How many miles on your plugs?
Did you reach down from the top to disconnect the conenctor or to repair it? Any chance you knocked off a vacuum hose or an electrical connector?

 

I did reach down from the top but I did look for a hose off or connector that might a been loosen, I did not see it, the truck has 90000 miles on it with orginal plugs, it was not missing before I changed the o2 sensor, I changed the drivers precat side. Is it possible that the new sensor is lean enough that it is causing a miss with the plugs? I pull one plug and it does not look that bad. I have no access to a scanner to see real time activity, just a code reader. The engine idles smooth and on slow or hard accelaration it will drop some cylinders, I cannot tell which ones are missing. Any suggestions?
Thanks Racerguy for your help.
David

 

You could take it to your dealer and have them do a cylinder power balance test on their WDS scan tool but at 90,000 miles I would just start by replacing the plugs. I haven't seen it before but I think it might be possible that now it's running with the correct air/fuel ratio and maybe the plugs are having a hard time firing that.

 

Well good news, I replaced the plugs but that did not fix the problem, I started checking the connections to the fuel injectors and as I would wiggle them the engine would change rpm, so I cleaned all the connectors and also cleaned the coil connectors, and guess what, it fixed the problem. Thank God!!!

Now to recap I believe the problem was encountered in the unpluging of the o2 sensor, as I would pull on the harness to get it unplugged I would move the engine harness enough that it changed the position on the connectors. I did find some of the connectors to have corrosion on them even though they are supposed to be water tight connectors. I hope this will help someone else.
I used to work for Nissan for 30 years and I know that the old Z cars were bad about the fuel injectors connectors getting corroded, Nissan even came out with replacement connectors that you could splice into the harness to correct the problem.
David

 

Good to hear that you got it solved
How long ago did you work for Nissan?
What do you do now?

 

I worked for them 3 years ago in Midland TX.
They are a good company. I am a Clockmaker now.
Thanks again for your help.
David