TahoeMatt

Hi -

My 99 5.7L Automatic is giving me fits all of a sudden.....
I get a loss of power and stuttering going up hills... also when on the freeway it will drive fine sometimes and other times after a bit it will start to stutter a bit and experience power loss ....

I was pulling a trailer the other day up hill and as I was going up the hill it seemed like there was an instance where it just dropped out and the power went away... ever since my hoe has been giving me these issues.

One code is random misfire.
The bank 3 and 4 are way off on percentage when looking at my obd2 monitor when running the engine.....

I was thinking that maybe one of my recently replaced 02 sensors went bad...I do have a bad exhaust leak that I'm going to repair this weekend...

Any suggestions or advice ?

Thank you,
Matt L.

go-part

When was the last time you replaced the fuel filter?
How old is the fuel pump?

shamrock246

whats the fuel pressure?

TahoeMatt

I replaced the fuel pump about 1.5 years ago.... did the fuel filter the same time.
Not sure what the fuel pressure is.

Would a bad pump drop performance on uphill climbs ? It seems like it's getting worse.

Bank 3 and 4 short and long term fuel trim is way off according to my scanner.
Bank 1 and 2 are fine....

Could this possibly be a coil issue?

Thanks for the help !!!!

shamrock246

These engines are sensitive to fuel pressure it should be between 60-65psi if you have a harbor frieght near by they have a tester kit cheap enouph i would start with that

TahoeMatt

gonna check it tomorrow..... it's throwing shi* now

PO340 - Cam Position Sensor ( A ) circuit ( Bank 1 Sensor )

P1345 - SGC ( cam position ) Sensor Malfunction / Crank-cam Pos correlation

I have no f'in clue what's going on....so damm frustrating.

shamrock246

How many miles on it?the distributor gears are know for wearing out and causing missfires and poor running i went with one of the aluminum distrbutors of Ebay with a 5 year warrenty