Dear Tom and Ray:

I make a religion out of keeping my vehicles for at least 10 years and 100,000 miles, but I've lost faith in my 1987 Nissan Stanza automatic wagon with 88,000. It has lost more and more power over the years. Now it can't even maintain highway speeds over any kind of hill. It drops down to 45 miles per hour and starts bucking and hunting for a lower and lower gear.

I've had three shops try to put the fear of God back into it by checking the spark plugs and timing, cleaning the fuel injectors and changing the fuel filter, but none of that has helped. It wasn't always like this, so I know something must be wrong. Do you guys have any ideas? -- Denise

RAY: Sure we do, Denise. They're worth every penny you're paying for them, but we do have ideas.

TOM: One possibility is that your catalytic converter is plugged up. When that happens, the exhaust gases can't escape from the engine. And if the exhaust can't get out, the fresh gas and air can't get in, and the result is, what? A loss of power.

RAY: The other problem we see frequently on these cars is a small crack in the hose that connects the air mass meter to the intake manifold. Why does that cause a loss of power? Because it fools the air mass meter into thinking there's not as much air coming in, so it tells the computer to send in less gasoline. And when less gasoline comes in, the car just chugs along.

TOM: It's very hard to see these cracks. For some reason, they're always on the bottom of the hose. That's why I always get my brother to squeeze his fat head in there and take a look. But your mechanic would probably be better off just removing that piece and inspecting it visually.

RAY: Those are the first things that come to mind, Denise. So take those ideas to your favorite mechanic and have him check them out. And if you need more ideas, write back to us and we'll be glad to go on for a few more Stanzas (ha, ha).