legacycentral bbs

So my buddy has an SS and he is on a road trip and needs me to post this for him. He said he is only getting like 9-13 MPG on the highway, it has like NO power, cant accelerate at all in 5th gear, vac at idle is only at 10, and idled really low like 500 rpms or less.

Not many mods done, just exhaust, desnork, coffe cup mod, KNN filter. He says all the vac lines are connected, and it holds boost fine. He said when he lets off the throttle it sounds there is like a "growling" noise coming from the intake.

If you have any ideas of what could be going on it would be greatly appreciated. He is on like 1700 mile road trip and this obviously can cause some issues. Thanks

Can he check the codes. Is there a CEL?

Maybe something got ingested into the intake, prior to the filter.

No codes. He is gonna check in the intake

Sounds like something in the intake system somewhere - As bad as it's running I'd assume it should be easy to find.

also sounds like a clogged cat, but if the exhaust was manifold back, that would exclude that idea.....

id check the timing belt, maf, spark plugs, wires, coil....

Sounds like it's simply misfiring is the CEL on??

no codes

ill have him check the other stuff asap and get back

Check to make sure the engine is firing on all cylinders. Pull each plug wire and see if the engine runs any different.