yup code never came back
thanx guys

 

glad it worked. those things are magic, eh?

 

Good to hear it worked for ya.

 

What is this fouler trick, can someone send me link to forum about this please.

 

You can gut out both your cats and run them like that all day, thought your CEL will be on at all times and you will be in open loop- uses set limits to run the engine, no compensation- and its illegal, though I ran without a cat in my VW for about a year and a half ^_^ I gutted it out myself.

An O2 sensor works by measuring the oxygen in the exhaust and thats all, it does not measures, nor see's ANYother gas. When it see's a huge difference it sets a CEL and tells the computer to go into open loop.

What the fouler or CEL elimter does is puts more space between the exhaust and the sensor, so the sensor will see the right amount of oxygen, and hopefully tricks it into reading normal, this is why it sometimes works and sometimes does not.

 

one more question about fouler's trick..

so.. to do the fouler's trick, all I have to is just take off the 2nd o2 sensor? The one under the car?

 

Yes you must take off the 2nd o2 then add the anti-fouler

 

The only cat you really need is one before the second o2 sensor. The first sensor reads the air straight out of the engine. you could have a straight pipe from the header to the muffler, as long as you have an o2 compliant cat before your second o2 sensor. That's how mine is set up. Just buy a $60 high flow magnaflow cat, put it before your second o2 sensor, and you'll have no CEL.

 

Hey i bought my car with 76k and i swear around 80k my CEL came on with the p0421 code. i have the obd 2 scanner so i've memorized this code by now. It never affected anythign but now i have 96k miles and i'm due for a inspection sticker soon.

 

It's still the catalyst efficiancy below threshold right? Either try a $15 CEL eliminator trick or get a new cat probably. One of those spark plug oil fouler eliminator things should work. Thats all the CEL eliminator lights are. But they're hit and miss but way cheaper to try out first

 

Do they mess with anything performance/gas mileage wise in the car? I always just clear them b/c I don't have any cats at all...

 

one thing you can do is relocate the downstream o2 sensor behind the second cat... Drill a hole , weld a bung in place , and extend the wiring for the rear / downstream o2 ... Our cars have 2 cat converters one in the exhaust manifold and one where every other car has em about midway thru the exhaust system, the rear / downstream o2 is really only testing the efficiency of the exhaust manifold cat and not the mid-cat... So if you want after placing the rear o2 sensor were it is suppose to go you can take off the downpipe take a long screwdriver and a hammer and gut the exhaust manifold cat.

 

CAnt' the evo ECU completely remove the need for the O2?

 

Tephra mod. I don't see why we can't do it too...

 

Good because I have a high flow cat and I put in a CEL eliminator and I STILL have the code.