Quick O2 Sensor Question

[94GrandPrix]

Does any 1994-1995 W-body use a downstream o2 sensor to measure catalyst efficiency? If not, can you delete the catalytic converter with no ill effects to the engine or computer? I live in a state with no emissions check so no converter isn't a problem.

[Schurkey]

The requirement for a converter is federal, not state. Therefore it's still illegal to tamper with it. The only thing you'd have going for you is that the feds aren't likely to inspect the vehicle...yet.

 

It's not like you're going to see "more power" from deleting the cat; assuming it's not defective and it's not the old GM pellet-style. The monolithic converters don't offer much back-pressure.

 

Really, how much is a generic cat--forty-five to seventy dollars out of Summit? I don't see the issue with replacing a defective cat as long as state law doesn't require an exact replacement . California requires exact replacements, there may be other places--that would increase the price considerably.

[tornado_735]

Cut the cat, and straight pipe it.

 

No downstream O2, and you won't hurt anything.

[94GrandPrix]

I knew that it was federal law, I was just asking a question about whether or not their is a rear o2 sensor monitoring catalyst efficiency in '94-'95 w-bodies. I'm not concerned about the state of my catalytic converter at the moment anyway because the car is going through a complete overhaul.

 

Where I live, I know people that have deleted their cats and had dummy o2 sensors installed (obd2 cars of course). One even had it done at a shop. Obviously the cars down here are not inspected.. period.

[94GrandPrix]

Cut the cat, and straight pipe it.

 

No downstream O2, and you won't hurt anything.

 

Good to know, thanks

[RobertISaar]

to answer the portion that doesn't involve tampering with emissions equipment, the only 95-earlier w-body applications that have a post-converter oxygen sensor are 94-95 3800 powered regals.

[rich_e777]

Wow dude, we have emissions testing in TN, where did you get your info from?

[94GrandPrix]

Some TN counties have emissions testings, others don't.

[Galaxie500XL]

True...Knoxville doesn't have emissions testing, though there have been several attempts over the years to change that. There's a muffler shop here in Knoxville that has pretty inexpensive cats...I've already replaced the one on my Buick wagon, and intend to do the same to my Cutlass--if they ever do pass emissions testing in our county, the cost for a replacement will likely be much higher. I'd prefer to be prepared, just in case.

Some TN counties have emissions testings, others don't.

[rich_e777]

Huh I didn't know it went down to county level discretion, they must be stricter here in Nashville because I always get the sniffer up the backside and a mirror ran under the car to see if a Cat Conv. is still there. They have checked the gas cap too but not every time.

 

Hey 94GrandPrix you could just hollow your converter out and leave it on just in case you have to be tested for one in the future. Run some "Guaranteed to Pass" and pull your PCV valve and you go right on through so long as the engine is running good. Maybe they will stop testing on my car so I don't have to worry about getting another larger diameter converter when I go to put a new exhaust system in.

[Galaxie500XL]

It depends on the "compliance area"

 

They've been trying to claim that Knoxville is not compliant, based on a single reading from a station 60 miles away, that showed high readings TWICE in the past year. If they can declare Knoxville's area noncompliant, they'll roll out emissions testing here.

[Nas Escobar]

Wouldn't be the first time that a state only does emissions in a certain part of the state. MD and VA are like that, but MD only has 1 or 2 counties that don't emission test. VA only emission tests in the DC metro area, and a little past down from that. Most of the state is a non emission testing state.