97 tahoe backfiring

[fktahoe]

1997 tahoe 5.7 vortec throwing a bunch of codes. p0430, p0175, p0302,
p0172. The truck backfires under mid throttle acceleration just a couple pops especially going from 1st to second gear. I have no cats and haven't had a problem for 2 years so I dont think its the cats, I have done cap, rotor, wires, plugs,and fuel filter. Any suggestions would be much appreciated.

 

[Mayhem]

Do a search for each code and look for a common issue. O2 sensor (possible from lack of cats) starts it and multiply.

 

[lwcools]

0430(catalyst system below efficiency threshold) is directly related to the lack of cats. 0302 is a misfire on cyl 2. 0175 and 0172 are system too rich codes. There's a lot of things that can cause the richness in the system, but I would start by investigating the misfire on cyl 2, and see what happens. Other issues could be dirty or inop MAF sensor or burned out o2 sensors.

 

[lesterl]

Check distributor cap, wire, and plug for #2 cylinder (front cyl on pass side). When replacing parts use NEW OEM GM parts.

 

[rockenthebowtie]

I agree with lester if that checks out ok you might want to see if you have the new updated fuel injector CPI unit because you may have a plugged fuel injector on number 2 cylinder along with a leaking fuel pressure regulator you can do the check by manualy opening up the throttle body plate get a flash light and look down the bore of the throttle body and you will see the fuel injector distribution tubes they'll most likely be covered with carbon build up which is normal for the most part you can get a good look at the front tubes if you don't see any electrical connectors you still have the old style type that cause multiple driveability issues such as the ones your experiencing