Stalling Lexus

My parents gave me their 1993 Lexus LS400 with 150k miles on it. The car was running great until one morning it wouldn’t start. I had it jumped and drove it aroud the block but it kept stalling on drive. I parked it and had it towed to the garage. The mechanic replaced the battery b/c it was bad but told me the catalytic converters (front and rear) are damaged and I need new ones plus a major tuneup. He said the car hadn’t been tuned up in years and this caused damage to the catalytic converter. See what happens is I can start the car after a couple tries, then I put it in gear and hit the accelerator lightly. The car just stalls out. The mechanic says the damaged catalytic converter is messing with the exhaust causing the car to shut down. I told him to take the catalytic converters out to test this problem and he refused to do this b/c he says it could cause a fire and it’d be dangerous. The mechanic wants to charge $3800 to repair the car. I’m not convinced that the catalytic converters are bad. And even if they are, I would like to take them out to test the problem. Is this a good idea? Do you think that this is the likely problem?

It is illegal to remove federally-mandated anti-pollution equipment such as the catalytic converters unless one is in the process of replacing them. In addition to other factors that make this a bad idea, it would be against the law for the mechanic to do what you suggest.

Correct. But how do you know that the catalytic converters are truly the problem? What else could it be? Please help.

If the car has really not been “tuned-up” in years, then this definitely would have led to damage to the cat converters. If I were you, I would begin by having ALL of the skipped maintenance done, and have the engine brought up to the best running state that is possible, given the possible cat converter problems.

Then have the mechanic check the car’s emissions. If the emissions are still out of whack, that would be a very good indication of either bad oxygen sensors or failed cat converters. Since oxygen sensors are not that expensive, replacing them would be in order, especially given the age of the car and its poor maintenance history. If you are really lucky, replacing the oxygen sensors will do the trick. If not, you just may have to replace those abused 16 year old cats.

Did your folks give you all the paperwork? How has it been maintained? What hasn’t been done that should have been done? You need to check this all out, let us know.