P06DD & P0520 back, with a side of P0420

H

hbar

New Member
Joined
Jul 20, 2021
Messages
14
Location
Prosper, TX
I replaced the oil cooler & both sensors on Friday. Within 30 miles all the codes cleared & all sensors were ready. Then today CEL came back on & at the same time did that thing where it won't rev beyond ~3500 RPM or upshift unless I let off the gas a little. Got home, checked the codes:

Pending:
P0420, P0520, and P06DD

Confirmed:
P0420
P06DD

Permanent:
P0420
P06DD

The 520 & 06DD were classified as permanent prior to replacing the oil cooler, so it's frustrating to have seen them clear and then come back. The 420 code is brand new. It's double frustrating because while I had the CEL off long enough to pass TX inspection, I am planning to sell this thing in the next few weeks (I prefer the TJ life) but selling with the CEL on is suboptimal. Any advice on these codes?
 
BLACKJKU said:
According to this the PO420 is a catalytic problem.

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Click to expand...
No kidding.

I guess I'm asking if people who get this code replace their cat or is it really an o2 sensor problem, or what?

And I also violated a cardinal rule of communication, I asked multiple unrelated questions in one breath... but those who have had the P06DD & P0520 and also replaced the oil cooler but still have the codes, what normally resolves the issue?
 
Did you have the codes before changing the oil cooler and sensors? What brand sensors did you replace with? I just changed my oil cooler and sensors but I didn't have and prior or codes after.
 
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