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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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P0410, p0420, replaced pump and valves, periodically drain

Customer Question

P0410, p0420, replaced pump and valves, periodically drain water, still gives code.
voltages seem a bit high on O2 sensor 3, but cat check passes. Help?
2000 S-10, 4.3
Submitted: 1 year ago.
Category: Chevy
Expert:  JOHN aka Eauto replied 1 year ago.

how did you test the cat?

Customer: replied 1 year ago.
I think the problem is the cat but the only fault shown is the 410,420, the cat passes the reader as it shows all checks passed except pump.
Customer: replied 1 year ago.
It passes "catalyst"
Expert:  JOHN aka Eauto replied 1 year ago.

have you performed a back pressure test?

Customer: replied 1 year ago.
No, you mean like put a potato in the tailpipe and check something? Just to let you know it did this since a new converter installation, it's just recently getting to where it does it almost all the time.
Expert:  JOHN aka Eauto replied 1 year ago.

was it a new aftermarket? new oe? direct fit? weld in? universal? and no not with a potatoe with a gauge threaded into the upstream 02 hole that measures converter flow

Customer: replied 1 year ago.
John, it was not oem but very expensive at about $450, as it didn't fit right I had to weld in a bunge to replace where the sensor would hit the frame. I told NAP A but they didn't do anything. I have welded in converters in my Ford van with no problem.I'm not that well equipped or smart but I keep trying. I'm thinking of welding in a new converter, the real problem is now a very hard to remove left side manifold has a broken bolt some I'm not wanting to remove it again.
Customer: replied 1 year ago.
I think I can weld in the type like on my van. I'm not familiar with the
back pressure check you mention.
Expert:  JOHN aka Eauto replied 1 year ago.

does it run good do you just want to eliminate the light? you can run cheaters and likely get rid of the po420... aftermarket conerters can be a night mare.. they do no always flow like a factory.. napa sells walker exhaust and its a roll of the dice if it will work