2002 chevy tahoe no power

[vvrepair]

I got a 2002 chevy tahoe 5.3 L with 120000 mi cust complained of no power. I checked for codes no codes. I looked at 02s they stays around minus 12 to 16. I tried vacum leak no luck also tried alt fuel at intake. Both downstream 02s are inactive. Thanks in advance

[Joe Rappa]

Hi VV
It's pretty unlikely that a vacuum leak would cause a no power problem. I'd forget that one. Are you sure you have O2s reading a negative number? That doesn't seem possible.
What's the fuel pressure when it has no power?

Joe

[vvrepair]

Joe got truck back to shop today checked fuel preasure under load 53lbs also checked cats. 1 to1.5lbs under load.Any ideas?

[Nickb]

Check in troubleshooter, and under system tip, there is a tip in there, no codes lack of power, that tells you about a very possible cause.

[akicestorm]

Have you duplicated complaint on a road test? If yes what was fuel pressure then? Have you cleaned the MAF sensor? Those are two most causes i see with those trucks.