Hello all, I did a search before posting but didn't see any topic already existing on this specific subject.

I just bought a 2007 Mazdaspeed 3 with 57,xxx on the clock.

I noticed today for the first time (seeing as I only had the car for a few days now) that when starting the car when the A/C is off but the fan is on that there is a gas fume smell coming through the vents with the air.

It seems to be running fine, and seems to go away after I start driving or if I turn the A/C on.

Might any of the wise Mazda experts here be able to help out a noob?

Thank you in advance!

 

Like I said, I'm a total noob but I suppose I can provide some more information. I have an aftermarket down pipe and cold air intake, aftermarket blow off valve and aftermarket exhaust from the manifold back, no cat.

I bought it with all of this done to it. I had a problem with the CEL yesterday but discovered that it was just the o2 sensor thinking the cat was bad since there isn't one. I'm told I need to put a spark plug extendor on the o2 sensor to fool it....

 

i had the same problem in an 01 focus zx3.... never figured it out tho... lol

 

I think I figured it out. It's coming from the upper left side of the engine compartment if you were looking at it head-on, kinda behind the intercooler and IF I'm not mistaken that's where the exhaust leaves the manifold and feeds into the cat.

Since I have no cat, it would make sense to believe that it's excess gas that's not being burned off in the (non existent) cat producing a smell.

Correct me if it makes no sense