If you don't have some sort of fix for the two o2 sensors, your ECU will be running in closed loop and dumping ridiculous amounts of extra gas into the mixture to keep it safe. With the 1st o2 sensor not even attached, you're obviously getting the same reading from both sensors and that's gonna throw the CEL. I'd get the MIL eliminator and that should solve your problem; although I'd get a nut welded onto the header as well so your o2 sensor isn't just dangling around in your engine bay. That's a pretty expensive piece you have there.

Sadly I currently don't have a car to work on or get gas mileage on.

As I stated in another thread... the car will NOT go into closed loop because of not having a MIL Eliminator (or open loop.. since it normally when running operates in closed loop.. see bottom of post). The car is still reading valid values and knows what the AFR is as long as the first sensor is in the header as it should be.

The CEL comes from the fact that the O2 bias between the first and second sensor is not large enough to match what the ECU expects to see. It says that is has an emissions problem.. not an engine problem and WILL NOT go into open loop.

And for clarity.. Closed loop is when the computer controls everything, aka feedback from sensor to computer to sensor to computer.. closed/circular loop.. Open loop is no control. It's just straight... i have X so I do Y... not Well I have X and Z so I need to Make Y into W which is what closed loop is.

SDH - i know you said in another post that your kamikazi header has an o2 sensor hole from the factory or whatever... can u post a picture of whwere it is? because i looked for a long time and could nto find anything

I'll try and get a picture tonight... but it's on the right side, a little toward the back, right about where the weld is where all 4 join into 1 I believe.

If you don't have it.. you just need to go to an exhaust shop and have those guys weld in an O2 bung... they'll charge you like 25-40 bucks.. and it'll make a lot of your problems go away. You'll still have a CEL (eventually... reset the computer after this one... it'll take about 600 miles probably before you get a CEL), but your gas mileage will come back.

what will make the cell go away and the gas mileage come back and all my other exhaust problems that we ahve been talking about go away?

Putting your O2 sensor back in.

Plain and simple.


You may get a CEL eventually/again.. but if you wire the resistor system into your rear O2 sensor then it'll be fine (DON'T put it into the first O2 sensor). But your gas mileage will be fixed, and the car will run a lot better/smoother.

Auto tranny should average about 220 miles reaching the last 1/4 tank. Manual guys usually hit +290 miles.

From experience, an intake makes the driver go a bit more lead foot. Header should improve +1 to 2 MPG, but w/o an O2 sensor it goes berzerk on the fuel.

I have no idea where to start to look for what resistor i will need for the o2 sensor. I guess i will start by asking the question

"does anybody know what resistor would work for our car" and then run a search, and then if not found there check the manual but hopefully i can find it fast!@

And then i guess onec i find out what resistor i need where i put it and such.

thanks guys