mcoon1987

So I’ve got a 2001 Trans Am, been throwing O2 codes for a while. Got all the Denso replacements, got the fronts done no problem. The old ones have been on the car a long time, at least 15 years. It’s a Midwest car. Needless to say, I cannot get the rears out. They are totally corroded and rusted on.

I’ve soaked them like 6x with PB Blaster, tried driving the car and getting them out warm, propane torch, beating the **** out of them, breaker bar, nothing works.

Car has LTs and no cats, do I even need the rears? Car was tuned by the previous owner, and it runs great so I want to keep it the same as much as possible to not have to retune.

Can I delete the rear O2s without having to re tune? What do I need to do that? Honestly I kinda want to delete one and put a wideband in the spot for the other if I can. Any help appreciated. Thanks.

gametech

iTrader: (1)

Their is a socket adapter you can get for air hammers that lets you use a wrench to turn a socket while simultaneously beating the **** out of rusted parts. You would have to cut the wires off the old sensors to get a socket on, but it is usually a pretty good last resort for situations just like you have.

B52bombardier1

Not having rear O2 sensors would likely throw a Check Engine Light so yes, a minor tuning change to eliminate that code would probably be required.

Rick

jond99

iTrader: (1)

If you don’t have cats then you don’t need them. Just get o2 simulators. I’ve been using them for 20 years on my Camaro. Then you can just Leave the bad sensors installed.

RPM WS6

iTrader: (3)

Exactly this.

No need for the sensors at all, they do nothing besides monitor cat operation. But you don't have cats, so...useless.

Not even sure that you would need O2 simulators. I'm sure the rear O2s were already turned off in the tune, otherwise you would have been getting codes for them for as long as you've owned it (because you don't have cats, so their readings would have always been outside the threshold).

The current bung threads might be destroyed upon removal of the sensor (if it's *that* rusted into place), so if you want a port for a wideband you might need to weld a new bung in place regardless.

the_merv

iTrader: (88)

If the tune was done right they would have been turned off, I'm wondering why they are still on the car in the first place if it has LT's and no Cats.

mcoon1987

My dad got the car around 08 and rarely drove it for 10 or so years, I got it about 2 years ago. He hadn’t really changed anything ever, so the previous owner for some reason put the rears back in after doing the headers and exhaust. It definitely has a tune, but I assume they are not turned off, because then why would he even put them back? It never made much sense to me. It has been throwing o2 codes, but I read headers can do that so I’ve just been re setting the check engine light with my scanner.

It was missing really bad, I was kinda chasing problems and throwing parts at it. It’s got 180k, so I figured some new sensors wouldn’t hurt anything, and since it was always throwing the codes maybe they were actually bad. The miss turned out to be a burned plug wire, got a new set of wires and cleared that right up.

RPM WS6

iTrader: (3)

If it's not throwing any catalyst related codes, then they have already been tuned out. It would not be possible to have no cats, functional rear O2s in place, but no cat-related codes without custom tuning or simulators/anti-foulers/some other sort of defeat device. If that were possible, then nobody would ever need custom tuning to pass an E-check after a cat delete.

G Atsma

^^^^THIS. I think it bears repeating that the ONLY purpose of the 2nd O2 sensors is to verify the cats' effectiveness/efficiency. THAT IS IT!
If cats are deleted these sensors serve no purpose and should be deleted when the cats are deleted.