o2 sensor on downpipe...

[Silverfox742]

I ordered in the header/downpipe with CEL eliminator from RRM and am curious how easily (or not) the o2 sensor in the downpipe is removed and replaced back into RRM's. Also how exactly is the CEL eliminator installed?

[Jameson_IXMR]

Our evos have 2 o2 sensors, one at the downpipe and another after the cat converter. The first one is just for ECU fuel trimming, but the second one detects the o2 after it passes through the cat. If it is the same as the first o2 sensor it will toss a CEL because that would indicate the cat is bad/missing whatever. A CEL fix is usually also called an O2 simulator, and probably connects to the wiring going to that SECOND O2 sensor, allowing you to remove the sensor all together. It pretends that things are normal and sends a signal back to the ECU saying everything is A-ok.

It seems like you could just toss in a resister in place of the second o2 sensor, but apparently the sensor lets out the signal at a certain hertz(frequency) somewhere between .4 and .8 volts I belive, which could be fairly hard to replicate. I imagine the O2 CEL fix you bought is a device like that, which would consist of a timer circuit to randomize variables such as frequency and really simulate the output of the stock o2 sensor. Hope that helps, good luck.

edit: I didnt see this was a reg. Lancer forum, but Im 99% sure that it's pretty much the same.

[otter]

Get yourself an O2 sensor socket from the auto parts store, it'll keep you from rounding off the sensor. Other than that, it's not hard to remove. The CEL eliminator just screws onto the 2nd O2 sensor and then into the exhaust pipe.

[DangerousDan]

look in the advanced DIY forum for a better solution.

[bruce988jl]

I just bought a specific box wrench to the right size... I didn't bother with a O2 sensor socket though I have used one and It works nicely. The hardest part with the install is trying not to strip the O2 sensor when installing/removing it to/from. A tip with installing the O2 sensor, pre-wind it the opposite direction that you'll be turning in so that you don't overwind the wires. I think like.. maybe 6-7 turns should be fine.

[DangerousDan]

I've always used a big crescent wrench, never had any problems. of course, my o2 sensors have been removed a few times

[ski10804life]

This might be a little late hav'nt been on her ein a while but i had the sensor wrench or what ever it is and it deff did'nt work i torre the threads appart and had to buy a new one to put in my new downpipe do be carfule. Alot of the times your exhaust gets so hot that it welds itself to the pipe threads then your screwed like it did to mine.

[Jameson_IXMR]

Use the proper size tools (I had a friend who used to use standard on metric because "It fits!". Oh god. Anyway the right wrench and a 2 dollar 3 foot PVC plumbing pipe from home depot will do the trick.