p0420: Seems to be a common problem

[AmanDave]

Well Then I read a lot of the posts but no one wrote that the solved the problem.

I have a 96 Ex, 4.0L SOHC manual trannie and unfortunatly i live in NY state where now you have to pass a emissions check to get your truck inspected. and my truck for the last 2 months has been throwing a 0420 code. I used my scanner and it showed a dead o2 sensor post cat bank 1 and i though that was the problem since i punched a hole in my cat about 6mo. before the light came on and i replaced that since it was loud and obnoxious. so i replaced the o2 sensor and now its reading normal mV and normal fuel trim as well as are the others. im not seeing any power or drivability issues or anything but that god forsaken light won't go out. I've already suffered one traffic ticket for a uninspected vehicle and i don't want another so i need to solve this.

So if anyone has actually fixed their dilemma with this code. could you please give me some insight as to how the heck you got it to go away without spending massive amounts of money. because well.. bills suck and i need to pay those as well

Any help would be greatly appriciated.

Thanks to all who read or post on this,

Dave

 

[zippee]

Change the front O2 sensor also. I had the same problem and that cleared it up. Were you aware that Bank 1 is the passenger side?

 

[raaizin]

From what I read changing the O2 sensor will not do anything but waste $50. If the sensor was bad a different code would come up. I had been struggling with this. My light would sometimes come on in 100 miles or as long as 10k miles. I finally tried this on the advice of another forum member and it worked for me. Good Luck.

http://www.brickauto.com/o2bypass/o2bypass.htm