How does TwEECer do with Emissions?

[Rusman]

Hey guys, I've been having a hell of a time getting my car to pass inspection. It's not that modified (LT's, MAF, gears, hi-flow cats) and is only failing on the low speed hydrocarbons. I've been told HC's is unburnt fuel and that the problem is most likely a leaky injector or ignition problem.

So, will the TwEECer RT unit that I have be able to tell me anything about emissions functions? I'm tired of throwing money at it and want to see if the tools I have now will tell me what's wrong. Otherwise, I'm taking it to the Firestone shop for a $90 diagnosis :(.

[Saleen91]

Well it'll only allow you to change calibration data and log EEC visible sensors. If you don't know what & where needs to be changed to fix your emissions issue then you could be looking for a needle in a hay stack.

What's your base fuel pressure at? If I remember right (Lee might be able to chime in here) having a lean setup will raise your NOX, having a right setup will raise your HC's. So, going by your other post, I would suggest lowering the fuel pressure a few pounds.

[Rusman]

The pressure on the adjustable FPR should be at stock settings. I forget what it is, but isn't it around 38 with vacuum on (or is that off? :)).

I understand that I might be looking for a needle in a haystack, but I was wondering if it would log information and then it could be reviewed to see something that's way out of line that might point to my problem.

[Saleen91]

Stock FP is 39# with the vacuum reference off. Double check what yours is at. If it's higher that may be your culprit.

As for datalogging, you can view your right and left o2 sensors to help determine if they're both switching fine and in good shape. If your LAMBSE is out of whack from side to side (the #'s should be similar) that could indicate an exhaust leak, stuck injector, bad o2 sensor, a cylinder not firing, etc. As for the rest of the datalogging options they can certainly help with a process of elimination. I.e. finding out whether or not your TPS is set correctly (< 1.0v at idle) and does it ramp up evenly as the gas is applied... Or does it jump around at idle (i.e. .9v to 3v w/out touching the gas). The same can be applied to your timing to help determine if there's a potential problem with your TFI/dizzy while at cruise/under load.

You can gain some sort of information about each of the options you have under datalogging. It's just doing the logging and deducing what it is you're looking at and determining if it's a result set you expect to see or not.

[Rusman]

Thanks Ben :). I'll see if I can do some testing this weekend and that will let me know if I need to just take it in to the shop for diagnosis.

[Chuck98GT]

Have you done a tune up on the car lately? Changed the oil?