NEED YOU HELP... Front O2's dead on my 02' V8 Mounty.

[Mussin]

I have been battling this problem since summer. I replaced the 5R55W this summer and this problem has been here ever since. The car idles extremely rough for 2-3 minutes then smooths out and everything's fine, it chugs. If at any time you try to drive it when it is doing this it pops through the intake (extreme lean condition) and is dead in the water, no power at all, Unless you floor it, then it comes to life! At first it was just a slight hesitation but as it got colder out its alot more pronounced. I had a friend of mine who worked at a local Goodyear bring home their scanner from work so we could do some trouble shooting. Well the front oxygen sensors are showing NO voltage, the heater circuits are working properly but they are dead. The back 2 are fine. I thought what are the odds of both sensors going out at the same time?? So I bought 1 replaced it and still showed zero voltage?!?!?!?!? Well like I said at first it wasn't a big deal but now its a real PITA! I dropped it off at Local lincoln/merc dealership this morning and they call me back saying they found my problem.... "Your front O2's are not working, they are showing no voltage".... He said they can replace with Ford O2's parts and labor $414 for two o2's!!! I told him don't worry about it. He also said all the circuitry looks fine going to the sensor just nothing at the actual sensor.

My question is What the hell is going on here? I laid under the car for hours looking for a pinched wire, cut wire, I found nothing, everything looks like it did before we swapped the tranny?

Anyone have a clue?

(2002 merc mounty 4.6l V8)

THANKS

Jeremy

 

[morziac]

i seen some sensors on ebay for about $30 each, maybe just give them a go bro

 

[Mussin]

I bought a new bosch unit a while back and tried it, still nothing.. Do you think I would need to replace both at the same time? I wouldnt think it would matter.

 

[Limited02]

So you did replace both? Or just one and the problem is still there?

 

[Mussin]

I bought a new one put it in looked at the scanner and it still read 0 volts... I returned the new sensor and put the old one back in. Im off to get my truck now ill see what the tech says... I can get 2 new ones for around $100 but im not sure its gonna fix it. Just cant understand why they both are dead and still read "0" with a new sensor....


Jeremy

 

[Mussin]

I talked to the tec who looked at it and he thinks there is a short in one of the o2's, he said probably from pulling on the wores to try to unhook them. He said it happens all the time, since they are hard to reach. He said he wiggled the driverside o2 wires and the pass side voltage flickered on and off. He said the driverside one is probably shorted out backfeeding into the other one. He said to change them both and problem should go away..


Jeremy