Could adding 93 octane to a stock tune cause the CEL to come on? I installed the MRT CAI on Saturday and it worked great (I'm using it with the TBS). I drove it around for a while that day and everything was fine. That night I ran her down to 5 miles to E. So, far the fun of it I filled her up with 93 octane. The pump acted funny and was moving very slow, so I only put 4 dollars in. When I got in the wife said it was pouring in and when I started I had a full tank (full tank of premium for $4). Anyway, about 20 miles later the CEL came on after just cruising down the highway, no hard driving. I reset the computer this morning and then put a bottle of heet in and topped off with 3.5 gallons of 87 octane. Well, 28 miles into that tank the CEL came on again. Do you think a higher octane would cause this? The MRT CAI is supposed to work without a tune. I know of a couple of people on here with the CAI and even Doug said it would work without one. I'm just looking for some opinions from the techs around here, thanks!

 

IMO, 93 octane will not THROW a CEL. The problem is in the current tune of the vehicle.

-Dan

 

Well, it's just the stock tune. I guess I might have to talk the wife into a tune from Doug. Or I'll talk to MRT since they said it would work without a tune.

 

This may sound stupid but....

Is the gas cap on tight?

-Dan

 

Yeah, I checked that right away, because I have heard of people taking it to the shop for that I swore to myself that I would never let that happen, LOL!

 

might be a bad fuel sensor...

 

I think I might have to put the stock CAI back on and reset the computer to make sure it's not the new CAI adding to the problem. I guess?

 

Before I recieved my Xcal2 in the mail, I ran 91 octane for about a month, before it finally showed up. I never got any CEL's, I would reinstall the factory airbox, disconnect the battery and run it for a few days stock. Then reinstall it and see what happens.

 

Get somone to read the codes and then you'll know. My bet is your running lean.

 

My bet is a bad fuel sensor, it's been a problem for quite a few people, and these are the EXACT symptoms. The telling part is the $4 dollar fillup, it's the first sign, then the C.E.L comes next.

 

Might want to ask Scott Hoag, president of MRT. He has his own forum for questions on this site...

http://forums.bradbarnett.net/index.php?showforum=93

 

Thanks for your input guys. It looks like it is either the CAI or the combination of the CAI and the tb spacer. I put the stock unit back on last night and drover her for about 50 miles and the CEL stayed off. The only difference between my setup and the regular MRT CAI setup is the spacer and I had to get a longer PCV hose to compensate for the intake. So, I guess I'll try it next without the tb spacer.

BTW, how much ticking do you guys get from your fuel injectors? The ticking on mine seems to be too much, but I thought I would ask around and see if others have a lot as well. You can only hear it with the hood open, but it is quite noticable then.