1999 5.3

[BINNCZ71]

Hey Fellas, read this site daily, rarely post unless I have something to add.

I have a 99 NBS ECSB Z-71. only mods are Ultimatepd Air Intake, PV Muffler Cat back exhaust, transgo shift kit , and an 02 PCM tuned by Nelson.

Been tryin to track down a loss in power for a while. THe last PCM livened the truck up for a couple days, then it went downhill again. For a few days after the pcm update, it ran great. It still runs ok, but is not as strong as it was.

No codes are being thrown. Truck has 80,000 miles. Plugs are good.

Any thoughts?

[RedHeartbeat]

Is the fuel pressure close to 58 lbs and does it maintain pressure when revving the engine? Is the air filter clean? Could the cats be plugged? Are you getting any SES codes? Is the engine pinging or rattling? Has the transmission started acting strange?

[BINNCZ71]

No SES Codes... Cats were replaced by GM about 25,000 miles ago.
Trans acting fine. Sunshaft was just replaced in it a few months ago as it broke. Don't know on the fuel pressure. Don't have a gauge..

[BINNCZ71]

The problem may have reared it ugly head today.

Lost first gear in the tranny, several loud pops, clanks, etc...

Bad thing is , sun shaft was replaced 5-6 months ago..

[RedHeartbeat]

Are you putting out that much torque or was the transmission not built right? I sure hope it is covered by a warantee.

[BINNCZ71]

No, Not putting out that much torque. Talk to the man yesterday, the sprague (spelling) gear went out on it. The truck has 80,000 miles, the sun shaft wasa replaced at 74,000 miles.