will a k and n air intake cause a check engine light

[aunttony]

I have a 1999 wrangler sport 4.0 5 speed with an after market K and N intake. The check engine light came on and the dealer said it was the intake that caused it. He claims it is quite routine because of the massive inflow of air. I have checked several forums and have yet to see this mentioned. Any help would be appreciated.

 

[xt master]

I have an CAI and my light didnt come on because of it.

 

[SteelHeadz]

Welcome to Jeepz. What was the DTC?

 

[aunttony]

I believe it was a vacuum. I replaced the gas cap and the code came back after a few days

 

[Bounty__Hunter]

The CAI will not throw a code itself, could be a vacuum leak or an EVAP issue.

 

[SteelHeadz]

Yup! that would be an EVAP issue.

 

[aunttony]

So how do I correct a evap issue? Is there another thread on this subject?

 

[SteelHeadz]

Your Evap. system DTc's are often caused by a vacuum leak due to a worn or cracked hose. Start by checking all the vacuum lines from the engine compartment all the way down to the rear right fender well where the EVAP canister and LDP is located..Replace the cracked hoses as you proceed.

 

[phall92139]

Your Evap. system DTc's are often caused by a vacuum leak due to a worn or cracked hose. Start by checking all the vacuum lines from the engine compartment all the way down to the rear right fender well where the EVAP canister and LDP is located..Replace the cracked hoses as you proceed.

Hey Mikey, I've got the same problem right now. Getting a P0442 - minor vacuum leak code. I've been looking at lines but so far...nada. Having a hard time trying to determine just how many vacuum lines there are. I've got an '03 but it should be relatively the same from
97 to at least '06, right? Do you know what the magic number of vacuum lines is?

 

[southtj]

Do you know what the magic number of vacuum lines is?

There should be a schematic under the hood. Actually on the bottom of the hood.

 

[SteelHeadz]

7 or 8 if i remember correctly. Todd is correct, there should be a schematic diagram under the hood. It's the VECI label..Let us know if you need locations of the components. for the most part, you can find the majority of the EVAP components on the right rear corner fenderwell.

 

[aunttony]

I found a line near the rear of the Jeep that apparently came loose from a T fitting above the rear axel. So far the check engine light hasnt come back on. Yee Haw, I hope that fixed it!

 

[kjegbert23]

I was looking at that same T fitting on my YJ when I replaced the shocks. The upper hose is worn. Not sure what that T fitting is for. The upper hose goes up into the drivers rear of the jeep and disappears. What exactly is that fitting for? I couldn't find it in the Chilton's or the Haynes. No check engine light as of yet.

 

[aunttony]

I assumed it was a vacum assist for the breaks

 

[Bounty__Hunter]

I assumed it was a vacum assist for the breaks

No such animal in the rear of the jeep.

 

[JohnnyO]

CELs due to K&N filters will happen on cars where there is an airflow sensor in the intake tube, primarily Fords, and will occur if you put too much oil on the filter. It's easy enough to clean if it happens, just some electrical contact cleaner and compressed air. I've had K&N's on my old Ranger and new Sport Trac and never had a problem.