I started having problems after the catilitic converter was worked on. I started on the interstate and couldn't accelerate over 30mph. It kept making a sound like POOF!POOF! over and over as I tried to floor it. I barely made it to the next exit. When I got out at a gas station there was smoke coming out of the tailpipe. The engine was still cold. My first thought was that the car wasn't allow emissions to clear out of the exhaust pipe. I took it to the local garage and they said it way the Air Mass Sensor. They replaced it with a rebuilt because they said that was all they could get for a car this old.They charged me $330 for the part. Well, it still isn't working right. I tried to get up a long hill to my home and I couldn't get it over 30mph. It's intermittent. But dangerous. Can you help me? I live in San Diego. The car has 130,000 miles on it. I bought it 2 years ago when it had 110,000.

 

First off, get your money back from that shop. You got totally hosed.

 

Well I shouldn't say hosed because those things are expensive. But I got a used one for like $30 on parts-hotlines.com

 

Do you think the catalytic converter is bad and is affecting my lack of acceleration? Wouldn't the failure to remove exhaust from the engine cause backup pressure in the engine?

 

I once used an engine degreaser and did not cover the distributor as they directed. Some cleaner got in the cap and under any hard use it would misfire perfectly in a rhythm killing my acceleration. When was the last time the cap's been looked at? The cat would not be my first suspect. Another thing that I've seen in the wrong mass airflow sensor put on a car. Yours should have a cylindrical thing right next to the plug. You can compare part numbers to know. Do you still have the old sensor?

Here's one I that should be the same as yours:Volvo 240 Air Mass Sensor- Air Intake- Volvo Parts . You can see the round thing. There's a flapper that allows preheated air to go into the airbox. If that gets stuck open it can fry the sensor. The thermostat in the air box should have been replaced. Also check and see if they adjusted the new sensor after they installed it.

The intermittent quality makes me think of a cracked cap with heating and cooling.

 

Thank You for taking time to help me. New information. I took it in and had it smoged this morning to see if the mechanic had used a new converter and if it was good. It was good, it passed smog, and the tech. said it was a new part. So I was wrong. I am taking it to a different mechanic to have the gas tank worked on, it keeps leaking and that won't pass inspection in Ca. I'll see what he thinks. The first time this loss of power happened i stopped at a gas station and smoke was pouring out of the tail pipe. It has smelled hot. Like something burned. But after driving it for a week it seems to be doing better. I will tell the mechanic about what you said on the mass air flow sensor. Thanks Again.