catalytic converter removed and not seeing P0036 and P0135

I purchased this truck 6 months ago and I have been tinkering with it and loving the experience.

One of the issues I wanted to look into was a check engine light based on P0036 (means that for the engine to operate properly, the engine exhaust should have a specific air fuel ratio) and also P0135 (Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)).

The previous owner said it was due to the secondary / downstream catalytic converter being removed. I have a catalytic converter closer to the engine and it looks like a straight pipe was added downstream and just before the muffler.

I guess this would make sense but with the converter removed.

My question is - would I be able to clear these codes since the converter is removed?

Also, is it a safe assumption that the removal of the cat converter is the cause of the codes or should I do more troubleshooting?

When it's running and started it does smell rich and I suspect the mileage is not as good as it could be due to the issues / codes.

 

What year truck?

 

It's a 2004 2.4l (sorry, it was in my profile)

 

Have you heard of adding a spark plug de-fouler to address check engine lights?
Might be worth a try.

Lots of vids on this subject...here's one for your viewing pleasure:
https://www.youtube.com/watch?v=DMvBbaA-lzo

 

That worked for me. Different vehicle but put an O2 bung in and spaced it off with a 90° fitting and put the O2 sensor in. No issues once I got the spacer the right length.

 

wow, great info on the de-fouler! I will look into it.

 

My bad... missed that.

 

Okay, ready to buy the bungs / spark plug defouler. Any guess what size diameter I need for the o2 sensor? 18mm?

 

Correct, 18mm..be prepared to drill.

I was surprised how much I had to drill the defouler, to allow the sensor to thread in properly.

 

THANKS! Yea, I saw the need to use a 1/2" drill to bust out the bottom restrictor. Many thanks!!