So I just swapped out the stock exhaust in my 2010 5-speed fit for a cold air intake. After installing everything, started up the car and it began idling very hard in the 500-1000 range and stalled out within 30 seconds. Initially thought this was the result of possibly damaged the MAF, but after swapping it out for a brand new one the problem did not go away. I'm able to drive it with the MAF disconnected and I'm 90% certain there are no vacuum issues. Not sure where to go from here. Any advice is appreciated!

 

Did your exhaust modification require you to unplug/remove any sensors? Are they all plugged in and plumbed accordingly? Any CEL or codes being thrown?

Can you please list what actual parts you used to modify? It may give hints or someone who installed the same parts may have advice. If it’s running without the MAF, I am wondering if the diameter of the intake is the same as stock. MAF might be reading high/low. Double check for vacuum leaks anyways.

Post pics maybe?

 

Also double check all electrical connections for corrosion and make sure its plugged in tight. Check your hoses by flexing them to ensure there’s no cracks etc. There’s a few tricks for checking for vacuum leaks you could use.

 

Sorry for the late response. I did solve the issue. Turns out the diameter of the MAF housing pipe was to large and it did not like it, so the air/fuel mixture was waaaaay off resulting in it stalling. Switched to a smaller MAF housing and now she's running great! Thanks for the helpful troubleshooting tips! Really saved my butt there.