I recently built a CAI for my HHR. The problem is that when the MAF is plugged in the engine starts to sputter and then stalls. If I unplug it, the engine runs almost perfect, but the CEL comes on and the tranny seems a bit rough at the shift points.

Anyone have any ideas on what would cause this, and/or how to fix it???

 

Are you using an oiled filter like a K&N?

That (excess oil up the tube), could cause the MAF sensor to foul eventually.

 

I opted not to use an oiled filter right away, as I've heard of the fouling issue on other intakes. Besides, the MAF problem is instant once its plugged in. I also know that there isn't anything wrong with the MAF itself, since I can put the stock setup back together and all is well again.

Any other thoughts, Mike??

 

Then it sounds computer related to me. Perhaps the increased flow is tricking the ECU. Have you tried driving it around a bit? It should calibrate itself unless your runner diameter and length is waaay off. We found that the HHR likes to see a little smaller diameter tube thean you would guess. Velocity must be kept up for the FI.

Hopefully snksknr94 will step in wih a REAL answer!

 

You disconected the battery so the computer reset and recalibrated right?

 

Yeah , I read on one of the cobalt forums that someone had a similar problem with a Fujita intake. It was suggested that he try just running around with it, hoping that the ECU would recal itself. Problem is that usually my engine dies before I can get out of the driveway. Maybe I'll try that in the morning.

The only other thing I've found as a thought is to by ZZPerformance's Mini-AFC 2.2 (its supposedly made for the Ecotec engine only), to program the air/fuel mix. Problem is that costs $180. That's more than I'm going to spend for a homemade intake.

 

I tried that, too. Left he battery's "-" terminal off for 20 minutes. Still had the same problem.

 

Get it scanned and see what code is setting the light. I can't help out with having a little more info. Other than that put it back to stock and wait until somebody comes out a CAI. You sure it goes back to normal after putting the stock stuff back on, sounds like maybe you damaged the fins on the MAF.

 

I'm positive about everything going back to normal when I return it to stock. The CEL turns off ( the CEL only lights when the MAF is unplugged), and the tranny feels smooth at the shift points. What's your opinion on running it for a little while to see if the ECU recal's itself??

 

It should recal itself after just a couple of minutes of running but if it is dying before that something else is wrong. Are you leaving the MAF unplugged with the home-made stuff hooked up? I kinda got that impression from your above statement. Do the cooling fans kick on when the light comes on as well?