Exhaust Noise??

[mcpga]

Heard a strange noise coming from the exhaust of my Excursion. I started it up and was letting it warm up (outside temp. was 36 degrees), I got out to put something in the back and heard a noise coming from the exhaust. It sounded like compressed air was shooting out of the exhaust. I got back in pushed the pedal a couple of times and checked it again and it sounded normal.

The only mod I have done was to install an adjustable icp mod (10K, 18K & 35K I think) about a month ago. I've been running it on 18k most of the time, in-town driving & no towing. Lately, I've been noticing more exhaust fumes when driving with a window down, I didn't notice the fumes as much before. After installing the mod, the "SES" light came on and the code is 1211. I did visual inspection of the exhaust system(stock) and I didn't see any leaks. Anyone ever heard this sound from an exhaust before? Also, should I be worried about the code? Thanks in advance!

[mcpga]

Also, before I installed the mod, an 0-ring in the high-pressure oil pump went out while I was on a trip, I had it repaired at a Ford dealership. They changed the oil at that time and I have noticed any further leaks. Could this have anything to do with the 1211 code? Could I still be having a problem with the pump?

[Logan]

Not sure what that code is, the noise could have been the change in sound due to your warm up valve closing. Since it was colder that morning, your truck could have closed it to build heat faster. I will make your exhaust noise a little different, and when you hit the gas pedal, I am sure it went back to normal and took it out of "warm up mode."

[mcpga]

Didn't know I had a warm up valve, that makes sense, it definately sounded like something was closed. Thanks.

[dercody]

code 1211 is, ICP not controllable, pressure above below desired, have no idea what that means, i just downloaded the codes from google

[mjm8602]

I have a 99 F-250 psd, and I hear the same noise when the truck isnt completely warmed up yet in the colder months, truck has 125,000 on it, with superchips programmer and 4" sraight piped exhaust, sounds like wind is blowing out of the exhaust

[Marty]

Loud hissing? Yes... EBPV closing to help "load" the engine and warm it up. Also notice that the idle is elevated and as soon as you hit the brake pedal (to take it out of park) it stops and the idle goes back to normal.

The SES light is common one from a chip or 5,10,18k mod. That's how the 10k in particular works, it tricks your PCM into thinking it has low ICP and bumps up the oil pressure. Another SES light that is common after a chip or K mod is an overboost light that will illuminated after reaching psi's of 22-24 and then go away between 1 min or the next time you restart your truck.

Neither of which are to worry about. Hope this helps.