98Zam

Ok, I have bought 2 02 sims, and I saw where they would "plug in". The wires that run to the cat's, right?

But on the stock 1998 exhaust manifold, it seems like their is one more wire running off it that looks like an o2 sensor? I have now bought after market headers, and their isnt such a connection on them..?


Basicly, my question is:


Do i just "plug in" the new 02 sims to the connections running to the cats????

98 Silver Bullet

iTrader: (28)

Plug them into the ones after the cats. The PCM uses the ones on the headers to determine how rich/lean you are running.

Fulton 1

iTrader: (9)

Just to expand on Steve's response - In a stock setup you'll have an O2 sensor forward of the catalytic converter and one behind for each cylinder bank (total of 4 sensors). The two forward sensors are used by the PCM to calculate a/f ratio, etc. The rears are only used to monitor the cats. Basically if your rear O2 signal matches the forward O2 signal then your PCM assumes the cat has been removed or isn't functioning properly. The rear O2 sensors have no other purpose.

Now, when you remove the cats, your rear O2's will report the "failure" and you'll get an SES light. To fix this problem, the O2 sims are plugged into the harness for the two rear O2 sensors (assuming the sensors have also been removed). This will keep the PCM happily thinking that the rear O2's are installed and all is well with the cats.

So, your new headers should have a bung in each collector for the forward O2 sensors. Just transfer the front O2 sensors from your stock exhaust manifolds to the headers, install the O2 sims in place of the rear sensors (and make sure to mount them securely with a zip tie or something), and you should be good to go. If you have longtube headers, then your front O2 sensor pigtails may not be long enough to reach the new location. In that case you can either use the stock rear sensors as the new fronts (they are all the same sensor just with different length of wire pigtail) or you can pick up some O2 wire extensions.

HTH

98Zam

Thank you very much for your reply, helped a lot






By chance, have any links on how to do the Throttle body drill mod and Clutch master drill mod? LOL! I have the motor and trans out, so I just really know the size of the drill and where exactly to drill. 2 Lines go into the master, and from what I could gather through search, drill the line that goes from master to slave, on the end that connects to master cyl. (i dont know why its so hard to find this in a search, i tried for a while)

Fulton 1

iTrader: (9)

This should help for the master cylinder drill mod: http://www.installuniversity.com/ins...r_cylinder.htm