Can the Throttle position sensor cause P0420 codes ?

[nyc4runnin]

So i keep getting the check engine light on even after I changed the A/F sensor and O2 sensor and MAF sensor. But this time I get another new code ....

P0120 - which points to a bad Throttle position sensor and P0420 which says either exhaust leak or bad cat ......

can a bad TPS cause a P0420 code to come up ?

Should I just replace the sensor and hope that it will make both codes go away ? Ive spent almost $400 in sensors this year already .... only 135,000 miles on it tho lol

 

[004Gunner]

Are you testing the sensors before they are replaced? Those codes seem to be completely unrelated according to the diagnostic manual. I have heard of the TPS being replaced fairly often, falling in place behind the a/f, rear O2, and the MAF. But I prefer to test the sensors before replacing which includes checking the resistance and function. Both the MAF and TPS can be tested on board without live data scanners.

 

[shawnstcyr]

These 2 codes should not be related. The only way I can think they would is if the TPS was telling the ECM that you were applying more throttle than you really were. In that case, extra fuel would have been applied. You would have to have been running really rich for a long time to burn up the converter. Again, this is highly unlikely.

 

[nyc4runnin]

Are you testing the sensors before they are replaced? Those codes seem to be completely unrelated according to the diagnostic manual. I have heard of the TPS being replaced fairly often, falling in place behind the a/f, rear O2, and the MAF. But I prefer to test the sensors before replacing which includes checking the resistance and function. Both the MAF and TPS can be tested on board without live data scanners.

Yes i did test them, and they were all bad ... i guess i'll get a TPS this week and hope it fixes the last of these codes, if not ... then I guess a new cat is in order lol .... anyone have a good suggestion for an aftermarket cat that's a direct bolt on ? Id hate to pay $1000 for 1 @ the dealer .....

 

[toytech76]

No. Not related in any way to each other

 

[SnowLizard]

:bump2:

BUMP to this topic for my issue...

nyc4runner... and anyone else...

what did you end up doing? did it work?

I have the P0420 code showing up, I've been digging to make sure I do it right (I think are cats) but then I noticed my A/F ratio on my Scanguage be reading 11.3 startup and 12.4 after warmed up I'm seeing on heavy acceleration 13.9 MAX, all of which is VERY rich... should be 14.7, yes I have bad smell out the exhaust, but not rotten eggs.

so it's possible that something else is wrong...
yes already replaced front/rear A/F and O2 sensors (99 limited CA emissions)

anyone else able to chime in?