Hi. I have a problem with my 1996 F-150. I was driving home the other day and just out of the blue my engine and exhaust started sounding louder than normal. It is really just more apparent inside the cab. Well, I took it to Meineke to have it inspected and the exhaust is fine, muffler, catalytic converter, etc all seem to be good. However the technician pointed out that something (which he couldn't seem to indentify) that is on the engine by the firewall seems to be broke. He did say it was something to do with the emissions system. Possibly the EGR or PVC? I am not really mechanical but can do some things. My question to anyone if they can help is what could go wrong with the emission system that would cause my exhaust system to sound louder? (only really apparent when driving or idle). Thank you to all who can help or maybe give me a few things I can check out. BTW, my truck has the 5.0L V8.

 

you have to admit "something on the engine by the firewall" isn't much of a description.
What does this something look like?
To what or to where on the engine is this something connected?
To what else is this something connected?

If I were to hazard a completely wild-assed guess; and that's all I can offer without more info, I'd say you're talking about the secondary AIR injection tube that connects between the heads. If it cracked under the check valve, it would give you lots of exhaust noise.

 

I think I know what you're talking about. I've had a few check valves break in the air pump system. It takes a B.F.Wrench and good penetrating oil to get them out. Lucky for me, they were on vans, where the inside doghouse gave great access to such things. Getting to it on a pickup is going to be a PITA. It's a cheap part, not technically difficult to fix. I think you need about a 1" wrench. You might try "gluing" it back together with some J.B. Weld.

 

I agree w/Tom - it has to be the check valve or crossover tube.

. . .

 

Same exact thing happened to me. It was the hose which connects to the y-pipe from the secondary air system. It's almost impossible to see - you have to reach around behind the engine and feel for it. Please do this with the engine cool...