Cascade Crew

QwkTrip · Posted: Mon Jun 06, 2011 5:37 pm Post subject:

Ha! So get this....

It turns out I can use the HP Tuner scanner function to look at data. I plugged it in and it pulled up a code that my handheld scanner didn't. The code is low voltage at MAF. Nice, so that explains why the SES light is on. So I start the car and sure enough the MAF sensor is dead. But remember.... this is the MAF sensor that made the car run better. I put the stock sensor back in and it is good, the SES light is off, but the car is back to it's old ways of poor idle.

I happen to get a call from the previous owner today and he tells me that the car was speed density tuned. The car should run the same with or without the MAF sensor. But indeed, it runs better without. So now I'm convinced the idle problem is the tune. Nothing I can do except let it be, or spend $500 on HP Tuner.

aaron_sK · Posted: Mon Jun 06, 2011 6:57 pm Post subject:

QwkTrip · Posted: Mon Jun 06, 2011 7:42 pm Post subject:

LS1 cars have both from the factory. The ECM compares the speed density values to the MAF values and uses what is best. I think what it means is he tuned it using the speed density tables. It should run better with the MAF hooked up. In this case it doesn't.

QwkTrip · Posted: Tue Jun 07, 2011 1:55 pm Post subject:

Yep, mid-90's today and the car drove great. No MIL light. No idle problems. I can even drive one gear deeper about everywhere because part throttle control is so good.

I guess I'm losing the MAF for now.