I’ve deleted the cat, now running straight pipe 3” exhaust. Check engine light is on now, I scanned the check engine light, the problem is coming up for the O2 sensor, why is this happening, and how can I fix the issue.
1999 dodge Durango 318 5.2

 

Which O2 sensor? You have several. (at least two.) Wasn't the front O2 actually screwed into the cat??

 

i scanned it send it said both have a short.

 

Unplug 'em, start the engine. You should see 5 volts on one pin, and 12 volts on another, other two will be grounds. (test on the harness side with em disconnected.) See what you get there.

 

Maybe it needs a tune up? Could that be the issue?

 

Depends on what the codes are. Given they are talking about a short, tune up likely won't do a thing for those... but, the engine may run better anyway.

 

Ok so back to the o2 sensor, I’ll try unplugging and doing what you recommended.if all else fails , willI have to put the cat back on?

 

Probably not. I believe you have an electrical problem. If you can solve that, then the lack of a cat may (or may not...) give you a catalyst efficiency code, but, those are easy to work around.

 

do you have any idea of what can cause a short to the o2 sensors?

 

It's exactly that. A short. Could be a bad sensor, pinched wires, melted connectors, or any of a number of other things.