I have a 1991 Ford F-150 with the 5.0 engine and it lacks power on take off. The engine idles fine but when I go to pull off it feels as if the truck is working hard but not moving as fast as the engine sounds like it should. Is this the sign of a restricted exhaust? I did notice the right side exhaust manifold appears to be cracked. I also wondered if the cracked manifold was a sign of exhaust restriction. The muffler is only 3 mos old.

 

welcome to fte. what trans do you have?

 

When I was losing power like hell my cat was clogged. So it's defiantly possible that exhaust restriction is the cause, and I know for a fact that exhaust leaks take away a lot of power.

 

How long has this been going on, and have you tried pulling any codes? My suspicion is that your cracked exhaust manifold is causing extra oxygen at the O2 sensor, setting a lean reading and causing your truck to run rich. A long term rich condition can cause a catalytic convertor to overheat, leading to failure. I'd replace that cracked manifold and see what results you get.

 

I haven't tried pulling any codes but I believe that both of you are right. I will hopefully get it fixed when Uncle Sam sends me a refund for the first time in years.. Thanks a million.