Just used datamaster for the first time, Awsome utility, but I got some results I was'nt hoping for. Lterm, and sometimes Sterm are running WAY in the negative. About 8% or 9%, which according to datamaster, means I'm running on the rich side... (Which I suspected by the smell of exhaust) Where in the heck do I start in figuring out why? Or what can I do to lean things out abit? My car is a 93 TA, with nothing major done to it. LT Headers K&N CAI, chip, !EGR, !CAT. I heard recently that the O2's need to be replaced with 2 wire heated O2's if installing LT headers. Is this true, and if so, would this be causing the richness?

 

Read the PCM tutorial here

http://para.noid.org/~lj/

 

Technically your car isn't running rich, the -8% just means the computer is subtracting fuel to correct for a rich condition. If your computer wasn't using a -8% LTtrim, then your car would be running rich.

You should really scan your LTtrims for several cells. Mine vary anywhere from 1 to -13% depending on what cell I'm in. My average LTtrims for all cells are -3% and -6% though.

I'm sure what you're smelling also is normal, if you run without cats your exhaust is going to smell pretty bad.

 

Thax Evilbox. That makes alot more sense. DUH! How do I scan for other cells? Also, what should my O2 sesor values look like? Right not they tend to jump up and down alot. I LOVE this program. I am learning SO much from it!

 

If you go drive around your car will go into different cells, you'll notice your LTtrims jump around. There should be a parameter somewhere that tells you what cell you're in. Your O2 values should jump around a lot, it sounds like yours are working fine.

If you want to learn about all these parameters, check out Injuneer's site:

http://members.aol.com/InjuneerZZ/ScanMast.htm

 

your car automatically jumps to another cell as you increase MAP and RPM. datamaster will show which cell you are in directly above the BLMs. O2 readings wont really tell you anything.

are the readings equal.. meaning does the left bank BLM match the right bank BLM?

do you have a fuel pressure regulator?

 

Both sides are running realatively equal, and as far as I know, the car is still running the stock Regulator.