I recently replaced the factory air intake for an after market cold air. I was told that the cpu would remap itself, however, it is causing the check engine light to come on and causing the idle to bottom out. I replaced the mass air flow sensor and that helped but its still running rough. Help Please.

 

What year, engine, and the specific codes would be helpful. This will help determine if it's the intake or something else.
Most 04-08 5.4L run lean with an intake and need custom tuning to account for it. The MAF and ECU reset cannot properly account for the change in MAF location and tube size.
Put the stock intake back on and see if the problem persists.

 

yep...our newer trucks run lean already, and then you throw a CAI on it? I'm not judging...I did the same thing but haven't had any issues. A tuner should fix things unless you have bigger problems. I'd put the stock intake back on until you can get a tuner. Best of luck!

 

same thing happen to my buddys truck he when and bought it wit one on it told him about php and the gryphon and he just to dum to know to get one his check engine light and its got the lean code in my book its not good go get a custom tune for it or do the gotts mod

 

Read this post a couple of times and still could not figure out what it was trying to say....

To the original poster: can you post the codes the PCM is storing? It's rare that installing a CAI throws a code, unless you were extreemly lean in the first place. The 5.4 runs lean in stock mode to get the best MPG it can. Installing a free flow air box and then an exhaust, it would indeed require a tune. You did not say if you had an exhaust installed as well.

Post the codes here so we can help.

 

Get a free code scan with the cai on....seems like there may be something more that just the cai is causing it. put the factory air cleaner on, clear the cel, take it back if cel light comes back on. do you have an oiled filter? Even if you put a new maf, excess oil can cause issues with the new maf.

 

I had the code checked and both bank 1 and bank1 were reading lean. I was told that when both are showing lean that there is an air leak somewhere after the MAF. I went ahead and replaced the CAI with the factory and left the thottle body spacer. After resetting everything it runs fine with no CEI. I guess I'll have to wait until I can get a tuner.

 

Ditch the TB spacer, it does nothing. Try the CAI again with all the connections tight. See if that helps. My money is on the TB spacer being your issue.

 

I doubt it. The CAI is causing your lean issue. Although the TB is a waste of space and not doing anything. You can run lean without throwing a CEL.