I dont think the extent is this bad.

You can go to Advance auto parts/ autozone and get a 30 dollar generic Bosch o2 sensor. You actually leave the existing wiring harness in tact at the plug, but instead chop off the old 02 sensor. Splice the wires here. I used butt connectors.

Color match the wires, 2 white 1 black. The 2 white can go in any orientation since theyre just wires to heat the 02 sensor to get it up to temp. THe black is the most important wire since its the signal wire.

240 tank= your 02 sensor is ****. I redid it and still got ~270 a tank (driving granny style, if i drove normal, it was like 250!). I replaced everything else but didnt think to recheck the 02 sensor. Pulled it all out and redid it and it fixed it.

Now if your old 02 sensor wiring has a split in it somewhere that you cant see, it can cause this too.

 

currently im about 500 over the limit for NOS. (no bottle yet either )

oh well, they wont know that until middle of next year.

 

If you need a replacement cat --- I have mine in the attic. I also have my stock chips. Car was sold --- 86-951.

Chuck 951

 

Make them check it under the correct specs, not 911. If they can't do that, they don't know what they're doing, don't pay for it and GO SOMEWHERE ELSE ! Yes, timing, injectors, chip, cat, O2 sensor can all affect emmisions. There is some limited timing adjustment possible in the DME Make sure the engine is up to temperature when it is tested. And if all it says is that a certain MPH has to be maintained, does it state that it has to be in a particular gear? Try running in a lower gear at the same MPH. Some places won't even test it if they see something that isn't stock (exhaust, air filter, cat ) on the car. Sounds to me like you should be getting it tested somewhere else to start with.

 

You can fatten up the mixture a bit to reduce NOx. The mixture has to be very close to find the balance. The air bypass screw on the AFM has a big impact on emissions I found. The IM240 test has a significant amount of closed or small throttle opening in it. Take a look at these graphs:

http://www.systemsc.com/graphs.htm

I passed the tough IM240 test here in Wisconsin with the orignal cat (177K miles). Some people have added 10% Xylene to the gas tank to bring down NOx.

 

You are running rich. Once you have fixed your 02 sensor find somewhere you can use a gas analyzer (3 or 5 gas) and set your CO per the manual its not hard at all, I am guessing your adjustment screw has been messed with in the past, and you have it running better now it just needs to be retuned.

Mark

 

Same state, approximately the same numbers. Final resolution was to reset the springs inside the AF meter and replace the brand new aftermarket, universal O2 sensor with an OEM one. Be careful, the universal O2 sensor made by BOSCH may not work and in my case, worked backwards. Spend the extra and get a OEM unit. This info cost me a little less than a grand to learn (along with some other work). I also have an aftermarket chip and it still passed emissions.