gasoline smell in engine bay

[Redline]

Did a search...found a few relevent points to my problem, but I need to confirm these since the post I found is almost a year old:
- faulty/worn O2 sensor downstream of cat will cause engine to run rich
- faulty sensor will cause poor gas mileage

Now, the symptoms that I'm getting:
- slight gasoline smell in the engine bay (getting into the cabin)
- kinda noticed a higher fuel consumption; gas needle is lower than usual as this point in the week (I usually fill the tank on Thursdays)

What I've done to the car recently:
- new exhaust piping from the cat back, using stock resonator and aftermarket muffler (just done this past weekend)
- engine treatment additive (to engine oil) about 2 weeks ago prior to emissions test.

Now, here's my question: what possible factors could cause the gasoline smell in the engine bay? Faulty sensors (in engine bay and/or downstream)? Fuel pump? Something with the new exhaust piping? Other?

I need some help...THX!


Redline

[karazy]

You should get a CEL if the sensor is gone. It's possible that you have a fuel leak. Sometimes it can be very hard to determine where the fuel smell is originating from.

[celica supra 83]

a bad catalytic converter can cause a gasoline smell too,this probleme sometimes occure with the newer corolla and camry.

[csaxon]

Leaking fuel injectors (worn pintle drips fuel into cylinder when engine off). Fuel injector O rings wear out and seep. Leaking fuel filter or fuel lines.

Misfires spray fuel into cylinder but you don't get complete or any combustion of fuel so you smell it.

[Kep]

Like csaxon said, injectors. Look closely around the fuel injectors. If there is a suspiciously clean area near one (or more) that almost always indicates a gas leak (Gas being a good solvent, it cleans the affected injector nicely).

I've also heard that the charcoal canister can sometimes emit a gas odor. Don't know how to isolate it though...

Kep