Smog code 0420p

anyone have suggestions for tackling this code?

 

Majority of the time P0420/430 is a failed catyletic converter but make sure you don't have any exhaust leaks first as that can also cause a P0420/430 to set.

 

Best way to test without a shop vac?

 

Listen/feel around with the truck running and look for any soot stains.

 

Will do. Visually I noticed there there are gaps around the exhaust flanges. I'll test those areas first

 

Make a smoke jar and pump smoke through the intake. Google "DIY smoke jar" and watch a few YouTube videos. Watch for smoke coming out of exhaust joints.

 

That's a great idea

 

leak test confirmed that there was a front o2 sensor that was loose. I tightened it and checked for other leaks. engine light is still on. Any idea how long it takes to clear if that was the issue?

 

You can pull the EFI fuse and that'll reset the ECU and clear the existing codes, but it would be better to pick yourself up a ODBII reader and clear the codes that way.

 

Mine took somewhere in the neighborhood of 50-75 miles.

 

thanks

 

yeah the ECU needs to complete an emissions cycle before it will reset a code on it's own. Certain driving parameters have to be met. There's a document on here you can search for if you want specifics to make it happen sooner, otherwise most people achieve it in a few hundred miles of driving more or less.