missing/cutting out

I have a 01 silverado 5.3 with 117k that has just recently started to miss or cut out around 45mph and when trying to maintain a steady speed. The service engine soon light was on and it had codes p0172 and p0175 set twice. I've cleaned my K&N air filter and the mass air flow sensor, replaced the plugs. Any ideas what could be causing this or what I need to try next?

What did you clean the MAF with?

I posted other times about my throttle body being dirty caused the miss/cut out (at 45 mph and 1500 rpms was the worst) I cleaned it and its been fine ever since.

Did you replace the O2 sensors yet? (beat you j cat :p )

Because its both codes its probably not an O2 sensor. Look to something else like fuel pressure regulator or intake gaskets.

i cleaned the MAF with MAF cleaner, i have also cleaned the throttle body when i was cleaning the MAF and K&N. How do i check the fuel pressure regulator? i tried to check for a leaking intake gasket by spraying the throttle body cleaner all around the intake and didn't notice any differences in the idle.

Because its both codes its probably not an O2 sensor. Look to something else like fuel pressure regulator or intake gaskets.Since it has over 100k miles O2 sensors would be a good thing to replace...

does this motor have a cap and rotor, or fule injected. if it has a cap pull it and look at the rotor and the top of the cap for arking.

Were you able to solve this issue? I'm having the same problem with my 2000 Silverado 5.3L. (but no codes)

Thanks!

Gremlin the truck does not have a cap and rotor. It has coil packs and an ignition module.

I have a 96 chevy 5.7L 1500 when not on the gas not really off the gas it has a bad miss it is driving me crazy I have changed the plugs,wires,cap, timing chain and no help yet please help me not go insane...

Joe :confused: