So I drive a Ford F-150 and this morning when I was on my way to work my truck was acting like it was losing power and it has been for a while but not to bad but this morning it was doing it bad. Well while I was driving to work it slowed down pretty bad in 3 and 4th gear 1and 2nd was fine tho. But eventually it started to smoke inside the cab so I pulled over got out and poped the hood no smoke was appearing but still pretty bad in the cab coming from behind the seat. I looked under the truck and the exhaust pipe was glowing red. What could be the problem? Sorry I have no idea what I’m really talking about if it sounds rough.

  • Welcome to Motor Vehicle Maintenance & Repair! Commented Apr 19, 2019 at 13:11

2 Answers 2


From your description, it sounds like you have a plugged catalytic converter. The glowing red exhaust pipe and lack of power is what would clue me to that.

  • A very common problem with F-150's. Both of the cats died on my friend truck.
    – Old_Fossil
    Commented Apr 20, 2019 at 1:32

I agree with the other two posts. An easy way to check this, DON'T USE YOUR BARE HAND, but have someone get in the truck and hold the accelerator down slightly so that the engine is revving at around 1000 - 1500 RPM. Put on a good leather work glove and put your and in front of the tailpipe. If you don't feel much pressure then you likely have a plugged catalytic converter.

If you vehicle is new enough there will be oxygen sensors in the exhaust system both before and after the catalytic converter.

A more sophisticated test is to remove the front and rear oxygen sensors one at a time and test the exhaust system backpressure with a combination pressure/vacuum gauge connected to a fitting screwed into the hole where the oxygen sensor was. If the cat is plugged up then you will have high backpressure ahead of the cat and virtually none behind the cat.

Make sure to only remove on oxygen sensor at a time. When you finish one test reinstall the oxygens sensor before removing the other.

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