Should I just do the no-fouler trick instead of buying a new o2 sensor?

 

If the PO just had a new exhaust put on.... what's the likelihood that the cat is hollow?

 

That is why I am guessing its an old O2 sensor that went bad. But who knows.

 

OK. So I am guessing that you do not have a scanner or code reader that can display live data.....Do you?

If you do, read each O2 sensor. Upstream reading should be higher than downstream. If not, one is bad, both are bad (not likely) or cat is gutted.

Knock on cat and see if it sounds hollow, or it it rattles like ******.

 

I do not have a scanner or a code reader. I'm going to try and mess around with it tomorrow. My little brother (whose a mechanic) is coming over. Hopefully it is not the cat as the o2 sensor will be a quick fix.

 

Good time to try a gallon of lacquer thinner mixed with hallf a tank of gas and idle at 2500 rpm for 30 mins or a good long drive at high speed to clean out the cat and burn off buildup...I saw its a commonly used practice by some...new 02 sensors are about $20 with shipping on ebay..thats were I bought mine.
I found my cat was gutted by the po.... funny I never got the codes even without the fouler...I discovered it was gutted when I replaced it because it was rusting out.

 

that explains it. If it is gutted then your rear O2 sensor should read LOWER readings. Since they are roughly the same as the precat sensor...it tells the computer that your cat is not working.

Get an O2 simulator: Only for post cat O2 sensor(s)
http://www.thefastman.com/o2simm.php

ran one with my 1996 with a gutted cat. Weirdly, I got a bump in MPG and better driveability. Same as Drew was talking about after changing his post cat 02 sensors (Us Cali trucks have 2 precat and 2 post cat).

 

If cat is gutted and that is the problem, the non fouler trick should work....OK....may work. Haven't tried it so I can't say should.

 

I get lower fuel trim readings and better mpg as well as low end grunt now that I replaced my gutted cat with a high flow and replaced the pre cat sensor although to old one was clean and appeared to be working fine...
I believe although no one wants to here it here that a gutted cat with the fouler trick will result in running rich compared to a functioning cat and sensor.

 

Yup. Bookmarked that about 3 months ago. Just waiting on the available funds. Figure if I wire that in and zip-tie it on top of the tranny and take the wires from the o2 and zip-tie those up high, when its looked at with the mirror at e-check it'll look stock.