Boom!

[Xtreme]

My car backfires under deceleration. I cannot figure out why.
First: No codes, had a code 52, which has been cleared.
The car smells like it runs rich, so I put a multi meter on vf and e1, at idle, it shows 0.17? I had heard that you want to see 2.5v or somewhere around there. I just calibrated my tps, as per tsrm. Other relavant info: My car has stock exhaust, with a small leak at the elbow/downpipe flange, and my secondary cat has been hollowed out, but has a small leak at the rear flange also. I get no fluctuation in voltage when I rev the car up, and I had the multi meter set to read "12v" My cel used to come on while driving, kinda like supragirls', but not anymore, since I did the SOGI ks rewire. I have not found any boost/vacuum leaks, although I dont have a gauge to check, but no whistling or shrieking from under the hood. What do you guys think? I am running out of ideas and have been searching all day (between working on the car), with no luck as far as curing the problem. Also, I changed two things- first, my fan clutch went out, so I locked it up, and second, I put a gallon of Zylene in the gas tank, with about 3/4 of a tank of gas already in it. That was yesterday, and that is when the backfiring started. If anyone has anything to contribute, don't hold back. thank you

 

[supraredliner]

The back firing is almost certainly cause by the hollowed out cat. Mine did the same thing after I hollowed mine out. Are you having any power loss or stuttering?

 

[Xtreme]

Supraredliner: I have a very slight miss at idle- due to an exhaust valve being a little too tight. I have yet to really get on the throttle, but after I fixed my knock sensor wires, it seems to run fairly well. I am almost convinced I have a boost leak somewhere, as my gauge sits at -4 at idle. The idle is a little shaky, probably from the valve issue, but I can't see the hollowed cat being the problem, especially since the primary cat is still in place. I'm probably way off on that last statement though.

Also: I hollowed out my cat about 2 months ago, and It just started backfiring. So it's not the cat. Any other ideas?

 

[Dirgle]

Is your BOV vented to the atmosphere?

 

[Xtreme]

Dirgle: BOV vented to atmosphere? No. I know the consequences of the WHOOSH!
my father mentioned the fact my timing could be slightly advanced, but I'm skeptical. I'll try retarding it slightly tomorrow. I am also going to try running it for a half hour or so on the freeway, maybe it'll clear some cobwebs, ya know? Other than that, all my resources (other than SM) are tapped Also, Ive checked my lower IC piping as well as everything on the top, and I can't find anything. -X