99 Grand Marquis loses power after it warms up

Would be nice to have the codes... Does it seem like it is holding back? Any change in the sound of the exhaust? Thinking maybe a catalytic converter.

That was 1 of my thoughts too. I drove the car home when i bought it, keeping my foot on the gas at stop lights, and it drove fine other than that. It does sound like theres an exhaust leak though

Still could be a lot of things. If the cat is plugged, when it gets hot it will be glowing orange. Another thing could be the Air Idle Control Sensor. The sensor and the port it goes into gets all gummed up and needs to be cleaned. This is a major source of vacuum, and need to make sure the sensor seals when re-installing. Also there may be vacuum leaks. You can take a can of carburetor cleaner while it is idling, and spray along the intake gaskets, throttle body and anywhere there may be vacuum. It would be nice to have the codes. This points a person into the right direction of a fix. As you can see it can be numerous things.

I miss the good ol carburator days. When all you needed was gas, spark, and air.

The concept has not changed, but the way we make it work certainly has...

It does idle fine after everything ive already done. But after it warms up if i push the gas it sounds like it could be pulling too much air, or something could be clogged. Like the cat converter. The car only has 124,000 miles and i paid $1150 for it. As of now i still feel like it was a good deal but if i have to drop $500 or $600 more into im not so sure anymore.

It is sounding like a catalytic converter, when plugged it will make that noise. Get the car hot at night, trying to rev it up once warm, leave the car running or have someone with their foot on the gas, and look underneath at the cat. it will be glowing orange if it is plugged up.

Will do. I appreciate it

RF, I think you are correct about the cat con. Dunno why but we've seen more than unusual here.

Any idea what itll cost me? Rough neighborhood?

Ford is about 2k, aftermarket should be about $500 for both. Let your fingers do the walking and call some of the local muffler shops. If you can find one use a locally owned shop that's been around a while, although old school guys are grumpy they usually do good work.

$500 for both? So theres 2 of them on it?

sounds like your catalyst converter's pretty sure their part of the y pipe. I think it's about $500

Well, I had it towed to a mechanic today. He said the converters are bad but they shouldnt be causing this issue. He scanned the check engine light and it showed cylinders 4 and 5 are not firing. He said its the coils which are supposed to be delivered to my house tomorrow

So you have a miss on top of it. Keep us informed, always like to hear about what was done...

Will do

SUCCESS!!! Just spent about 45 mins in 20 degrees changing the coils in the mechanics parking lot. Im not gonna pay someone $150 to do something I can do. When i fired it up i could see the engine shaking from the misfire but after 2 or 3 mins it smoothed out and purred like a kitten, other than the catalytic converters making their noise. I appreciate everyones input and suggestions. Now I know where to go if I have any other issues

Good to hear...thanks for letting us know...

Glad that the converters weren't causing it to not go and you have your car back running again.

Got another question guys. Could the muffler alone cause these symptoms that made everyone point to the cadalytic converters

No, only if someone shoved up something in the exhaust to block the flow.