99MUSTANG5.3L

I have a 2004 5.3 swapped into an 01 Mustang,when the O2 sensors are plugged in it runs horrible. I put new Bosch O2 sensors in and it didn't clear up. I checked my wiring at the sensors and it's good(ground,12V,and sensor ref.).I did have a p0155 code but so far it didn't come back. Is there some kind of relearn for the ECU and O2 sensors?

It runs really well when they are unplugged, any help??

Old Geezer

iTrader: (3)

Harness plugs crossed?

99MUSTANG5.3L

Not sure what you mean. I only have the front 02 sensors from the truck harness. I have bank 1 sensor 1 plugged in and bank2 sensor 1 plugged in, does that sound rite?

Old Geezer

iTrader: (3)

that sounds rite..... Unless you have bank 1 plugged into sensor 1, bank 2, and vice versa....

BOTTLE ROCKET

iTrader: (4)

This is actually a common issue

99MUSTANG5.3L

I'm thinking about just getting those O2 simulators and be done with it!

99MUSTANG5.3L

Found some generic O2 sims on ebay. Any other resouces for sims that you guys have used?

Old Geezer

iTrader: (3)

You still haven't answered the ???
The sims are NOT the way to correct the problem.

99MUSTANG5.3L

Which bank is which? I was unaware that it mattered since I'm only running the fronts. I traced the wiring back to the ECU to make sure that I have bank 1 sensor 1 and bank 2 sensor 1 and I do. Both sensors are located before the cats.

Ya, I am aware that the sims are not the answer, just kinda frustrated with these o2 sensors is all.

CancerJCC

iTrader: (4)

He means they are not the answer because your front O2's are used for fueling. Unless you are in OL all the time then the PCM needs those O2's to correct fueling...

99MUSTANG5.3L

Ya, I know they are used for fueling. I am running in open loop right now because I can't figure out what the problem is.

99MUSTANG5.3L

No more suggestions? I'd really like to get this fixed.