CEL confused about a few things
 

Recently, when I WOT (Wide Open Throttle) the car, the check engine light comes on and the car goes into limp mode. Turn off the car and turn it back on and it goes fine except when I WOT, the car feels like it has no power.

I changed the MAS a year ago so i'm suspect on whether it's the MAS again.

I have a few question if someone would be so kindly to answer.

Does a plugged fuel filter set off the CEL? (What are the symptoms of a plugged fuel filter?)

Can bad coil ends cause the CEL to come on?

I went under the hod of my car and added revved up the engine. Each time it revs I hear a hissing sound. Is this normal or a vacuum leak somewhere?

I haven't had time to pull the codes but I will this weekend.

Thanks,

Rocky

Hey Rocky, what codes are you getting? If you're getting mis-fire codes, especially from the same cylinder bank, you could have a clogged catalytic converter on that side. I've seen this happen many times on different MB's(220's, 210's, etc.). The exhaust system "breathes" fine, until WOT. Let us know how it goes.

Can't be the cats, I just changed them 7-8 months ago under warranty.

What codes???

Misfire in #2 cylinder. Replaced 3 coil ends and 6 plugs. Car runs like a champ now.

Now I have ot find out what that whirring noise is when I accelerate.