08 silverado.idles great.get it on the rd.has no power.cant even get it up to speed.

[Tpeterson]

 My 2008 1500 Silverado.lost power when i accelerate.it might do 20mph.

New plugs.new wires.new coil packs.new injectors.new oil change.i get 45 psi at the fuel rail.tell me this is normal.i got the fuel pressure reading 45psi.shut the engine down.After about 5 min the pressure reads 60 psi.after 10 min its 70psi and holds. For 10 min.now its coming down 68 psi.

Is my tester bad

Id appreciate any help.

[swathdiver]

43.5 psi is normal operating fuel pressure.  How are you fuel trims reading and your O2 sensors reading?  Any engine or chassis codes?  Is this a sudden problem or has it been lingering and just gotten worse over time?

[CamGTP]

Plugged exhaust comes to mind.

[Tpeterson]

Your exactly right plugged cats.

I cut the pipe behind the cats cleaned them out.tacked the pipes back on.it runs like a champ.it has lots of power .maybe more power than before.

Heres the thing .it didnt throw any codes.not even lean codes.the only code was a p0300 im using a $15 dollar ob2  code reader.now ill go have new cats installed.thanks for the feedback i appreciate it alot.god bless

[T-Town-Z]

Just curious how many miles you're at ?   

Any idea what may have caused it ?