code p0420

[Leroy73]

Hi, im ready crazy for months try to found the problem with my 2010 chevy equinox. The RPM is moving high to low, when put the hazard light all interior lights start blinking and i dont know if is same problem now show me code p0420. My question is... a bad high pressure fuel pump or alternator can cause those problem with the rpm of code p0420?. Im ready changed both oxygen sensor, catalytic, spark plugs, exhaust manifold, MAF sensor. Please somebody can help me?....God bless everyone.

 

[Hey Vern!]

I would start with the blinking. Have the battery and alternator tested to make sure they are not the problem. If they test good you may have a bad ground someplace. Hopefully that will solve the RPM issue, too. The P0420 is catalyst inefficiency. This could be o2 sensors or catalytic converters.

 

[PoManNox]

I agree with @Hey Vern! I'd start by checking the battery connections and wires. I would then load test and then crank test the battery with a digital battery tester. You need to do both for a true health report on the battery.

Then I would address all the parts that were changed. Were these aftermarket or OEM parts? So many aftermarket parts are junk right out of the box.

 

[Jakebot]

Hi, im ready crazy for months try to found the problem with my 2010 chevy equinox. The RPM is moving high to low, when put the hazard light all interior lights start blinking and i dont know if is same problem now show me code p0420. My question is... a bad high pressure fuel pump or alternator can cause those problem with the rpm of code p0420?. Im ready changed both oxygen sensor, catalytic, spark plugs, exhaust manifold, MAF sensor. Please somebody can help me?....God bless everyone.

Just so it's said, if you replaced your catalytic converter with the wrong one, similar issues can occur. There's a sticker under the hood that will specify whether or not it complies with California emission regulations (Even if you live nowhere near near California and your vehicle came from nowhere near California). The non California compliant catalytic converters are substantially less money, so it's common for people to make this mistake. Don't ask how I know.