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GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15181
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: 10 months ago.
Category: Chevy
Expert:  JOHN aka Eauto replied 10 months ago.

how did you test the cat?

Customer: replied 10 months 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 10 months ago.
It passes "catalyst"
Expert:  JOHN aka Eauto replied 10 months ago.

have you performed a back pressure test?

Customer: replied 10 months 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 10 months 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 10 months 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 10 months 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 10 months 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

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