ok guys gonna throw out a random question, and despite the fact of "bad for the environment" arguement..
ok so we all know if you hollow out your cat convertors your downstream o2 sensors go dumb and kick cel.. of course i live in a wonderful county/state that requires emissions which if there is a cel its a auto fail...

question is, i have heard tha you can put a resistor in line with the o2 and fool the computer, what size resistor would it need to be and on which wire would it need tied into, i know there is 4 wires coming out of o2's, also i have heard yes it throws everything out of whack when cold, i thought that one through too, a 3 pole toggle switch, 1 pole being the wire with resistor, and the second without,showing proper readings for cold starts..

now i know ive thought this through all too much, and is probably more of a hassle than ever worth, but wondering if at all feesable, moreso to prove a point rather than trying to kill the environment..

and thank you if you managed to stick through this whole hair brained idea

sorry its a 2002 f150 with the 4.2l 5 speed standard

 

The sensor monitors Ox storage from the cats.
The PCM looks at the ratio of rear to front switching to indicate the relative health of the cat system.
Two of the leads are for the sensor's internal heater.
The PCM also monitors this for current draw, opens and shorts.
Good luck.

 

Exactly. In fact wiring resistors decreases the voltage of the sensors. Low voltage means more oxygen. More oxygen means the cats aren't functioning, so wiring a resistor is the opposite of helpful.

Simple fact of the matter, the stock cats, if kept properly maintained do not cost you power, and they are not a component waiting to fail.


The only reliable way to ignore the catalyst monitor, is to alter the vehicle program via a tuner like SCT, which can just turn the sensitivity way down. sure some people are able to fool the system into thinking there is a functional cat, but you are just as likely to trigger fault codes for non-responsive or out of range sensors.

Also, the environment the cats most protect is yours. Nature int he long run really couldn't care and we have very little effect on the environment in general. But the areas where people live can become more hostile than the surrounding areas. Asthma, allergies, various breathing problems, etc. can be aggravated by vehicle emissions, and carbon monoxide is colorless and odorless, and it has a cummulative toxicity effect. The cat is there for your safety.

 

I do understand all that.. and great info on th resistors actually doing the opposite of what I thought.. like I said it was more of a "I'll prove you wrong" cause a good friend of mine said it is "100% impossible to cheat the o2 sensors... my cats are in great working order,even tho I do a downstream o2 going crazy due to a bare wire(damn drive shaft lol) but it was more of a "prove ya wrong" theory here... I know dumb to destroy 5-600 dollar cats to prove a point, but that's all it was for in long run.. plus I'm sure it woulda made more noise which isn't always bad lol.. anyways we will have to disagree without proving either one is right... it isn't worth the money lost.. plus you do make good points on the personal immediate hazards.. thanks guys.. consider this one closed up lol