I recently bought a 1992 BMW 325i that was not running. I was able to get it running, but it is not running well. It is missing and backfiring through the intake. When I press on the throttle there is a delay in response and will not run at a constant throttle position. I have installed new plugs which helped it run a little better. The previous owner did tell me that the car had been sitting for almost a year after his wife ran out of gas and he attempt to get it started by putting more gas in the tank, but was unsuccessful. Last night I was running the car and notice that there was a lot of smoke coming from under the hood only to find the lawn underneath the car on fire. The catalytic converter was apparently overheating and set the grass on fire. I activated the self diagnostic on the car and got a code of 1215, which is the MAF sensor, but I don't want to spend $200.00+ on a part that is not needed.

Do you have any idea what the problem could be?

Thanks.

Possibly retarded timing. The DME will be suspect as the timing is controlled electronically. Try to get a timing light on it if you can. A plugged cat will do this too.