ford88

Well I was going to install my new x-pipe and catback last weekend but saw that the 04 only needs o2 extensions even without having longtubes. Would it harm anything if I were to just install the midpipe and mil eliminators. Or will not having rear o2s mess the tune up and make my car run like crap?

I think this is tech forum worthy, move if it isn't please.

5sp04GT

when i put my h pipe in i used all the things i was suppose to o2 sensors mil elims, and extension harnesses. Because if im correct not using either the o2 sensor or the mil elim will result in a check engine light. you have to use the extension harness as the factory harness isnt long enough. your new midpipes rear o2 bungs are located farther to the rear of the car than the factory pipes were.

cliffyk

Whether or not you need extensions for the rear sensors depends on how the new mid-pipe was fabricated, many do not require any extensions (my UPR catted X-pipe did not).

As to the rear sensors, all they do is monitor the efficiency of the catalytic converter--not having them connected/installed will not affect engine operation, it will only trigger a DTC and light up the SES lamp.

If you are installing an "off-road" mid-pipe with no cats then you will get the DTCs and lamp even with the rear sensors installed--once again this will not affect engine operation. To correct this you need to use MIL eliminators to trick the PCM into believing the cats are there.

You can make your own for $5 or so.

MIL eliminators filter the signal from the rear O2 sensors to reduce the voltage level and slightly alter the phase of the signal to make the PCM believe the catalytic converters are there and working. This means of course that the rear sensors must be installed and fully functional or there would be no signal to filter.

sv650lex

[QUOTE=cliffyk;6769155]

You can make your own for $5 or so.

QUOTE]

This is what I did it also extends the wire length a little bit. It's pretty easy if you have a soldering iron.

3ohtwo

I just used 12" extensions on my catless h-pipe and just deal with the check engine light.

pcs

extensions and mil eliminators are cheap enough to get, not good to run car with the cel on bc u might not know when u actually have a problem with the car. the "idiot" light is there to help you out. if you trigger that light to come on your car might not run right because the ecu will think their is a problem with the cats then mis adjust your a/f ratio to compensate for the bad signal its getting. some people say their car runs good but other say it doesnt.

3ohtwo

Mine runs with no problem with it on. I'll clear it out every so often and it just randomly comes back on. Usually after I drive it hard, then hit the highway and put it on cruise. But no issues with missing or loss of power etc...

Nestang

I had mil elminators to begin with, but my diabo sport shuts it off as well

smitty2919

right, but do you check the codes every now and then? otherwise you could be clearing something that could actually be a problem...

just get the MIL's then when the light comes on you can bet it's not due to the O2's and it's something you need to look into.

for my 04 i picked up some O2 bungs from an exhaust shop and relocated them...no need to buy $30 extensions when i picked up bungs for free and adds an extra 30 min for install to drill and weld them on. BTW i have a UPR O/R x



relative location where i moved them to: