88 celica problems...again?

[CelicaGirl]

Ok....so I love my car. I haven't posted recently on here. I went to the Toyota dealer down the street and they told me my car was an after market convertible. They sent so many to another company to be made into convertibles and then sold them. Which would explain why I can't find a rear window lift motor and weather strip designed for my top. I can live with my rear window not going down and I can live with the wet seat.
The big problem I'm having right now is that my car used to get 33 mpg now it's getting about 18. What's the deal. It's chugging gas like a pig. I also smell fuel while driving. I check for leaks and there's not a leak. I change my oil frequetly and give it a tune up about every 2 months. I think the problem also has something to do with my car backfiring. There's no certain time when it back fires. I'll be going around a corner and it'll do it or I'll be going down the highway and it will do it. I don't change gears or anything. I'm just driving. If you guys have any advice please let me know.
I'm not going to be driving this Celica for much longer. I'm getting an 86 hardtop coupe and that's going to be on the street. The 88 convertible will be in the garage as my fiance's project. So let me know if there's a quick fix for my problems. I really appricate it.

[jwaj2002]

o2 sensor or cateletic converter, o2 sensors are cheap start with that, the cat converter your going to have to go a muffler shop for

[Dahhavahiid]

Hi I have an 88 Celica GT convertible also, but my problem is that I'm not getting any fire whatsoever to the sparkplugs

[Brian R.]

First thing to try is check that you're getting 12 v at the distributor. If so, replace your ignition coil.