Threw a CEL- suggestions?

[mndsm]

Long story short. Car threw a CEL this morning on my way to work. It was downpouring, but I don't have a full CAI, so I'm not thinkin' hydrolock. I have a custom intake manifold, as well as the TIP on the intake side. Intercooler is stock, have an uprated BPV as well. When the car threw the light, it started idling about 250rpm higher than normal. There was no funny sounds coming from the engine that I could tell, other than the usual lifter tick. One thing to note about the mani, it does have the VCTS removed, and is flowing about 100cfm higher than stock. I'm thinking there's a vac leak somewhere, simply because I don't have any other ideas. Haven't pulled the code yet, might go do that over lunch.... just wondering if anyone else has a though to the matter.

 

[Wagonbacker9]

hydrolock wouldn't throw a CEL... it would throw a rod.

get the code scanned. Autozone does it free.

 

[mndsm]

Welp, went to autozone, got the code pulled. Threw a lean idle code at me. Tells me that the car might finally be angry with my IM. Or possible vac leak.

 

[Jchouin1]

intake mods require maf calibration if you want your afr AND fuel trims to be accurate. even if your actual afr at idle is still 14.7, if your fuel trims are pegged 25% positive, the computer reads lean and throws the code. get a tuning solution.

 

[mndsm]

Yeah, that's on the list. Thanks for the heads up though. ECU's been pulling PSI since the mani got installed, and I want my boost back.

 

[MSMS3]

Vacuum leak. Methodical rechecking of every line, hose, tube, connection.

This is assuming that you were running well and without CEL's for a reasonable length of time with the intake mods you have. If the manifold and other changes are all recent and you immediately threw the code, then there are a lot more possibilities including a crack in the manifold, poor workmanship, etc.

What is an "uprated BPV"? The stock one will hold boost well beyond the capabilities of the K04 turbo's efficiency range. I assume it is running full recirc.

Have you checked the MAF sensor? Might need to be cleaned.

There are a host of other possibilities.

I still think the fast idle points to a vacuum leak somewhere.

 

[JReichle1]

Check for vac leak, would explain "pulling boost" and fast idle.

 

[mndsm]

Intake mods have been on the car for a year and a half. Uprated BPV=Forge in full recirc. As far as why it's pulling boost..... well that is an interesting one. Car's been doing it since the intake manifold went on. Apparently our ECU's are set to look for a power target... and since the manifold allowed the intake side of the car to flow that much more efficiently (25%+ variance between runners, to about 3% variance, +103CFM) the car decided it only needed 13 psi to hit its target. The manifold was actually the first thing to go on the car, as when all the testing was done to bring the product to market, we wanted every stage of dyno'ing possible. That's a story for another time though. I have a feeling I know where the leak is though, simply because for whatever reason, my CP-E Nano fits goofy, and the oil return bung causes the vent from the valve cover to rub on the underside of the hood. I could cure this easily enough, but I've been lazy. I think the car *could* be running lean at idle, because the VCTS is LONG gone, but it seemed a little odd that I'd be running like this for as long as I have, and just now throw a CEL. I'll be going through and cleaning the MAF and the intake filter, checking all my upper vac lines, and going from there. Probably just replace most of it with silicone lines if I can find someone that's got some stuff local at whatever random hour I decide to fight with it.