P1138 Code
 

1997 XJ6 with P1138 code plus exhaust just started not coming out of the passenger side tail pipe. What type of O2 sensor would I need to buy. Since I'm not sure about it being upstream or downstream. Any help?

I expect you realise this, but if there's really no exhaust coming out of one of the tail pipes, you're in need of more than a lambda sensor!

Does the car have 2 separate cats or is the exhaust mostly one but it branches off? I was originally getting the P0430 code but now it has switched to p1138. Any ideas what's wrong

Im getting that Code popping up, im thinking its one of the downstreams. I wish it would tell me which one.

Guys: It just not that easy that it tells you (or the ecu) which sensor... If the sensor is reporting "bad" data, then either the data (lack of cat efficiency in this case) or the sensor is bad. But you don't know which it is. The correct diagnostic procedure is to scan the sensor feedback and watch for "cycles' A little google will help you figure it out.

BTW, P430 and P 1138 are apparently different banks, so pay heed to the first "Possible Cause" shown in the attached picture!

USA car = 4 cats and 4 O2 sensors! The code tells you that it's the second sensor (downstream) on the front (cylinders 1,2,3/Bank 1) exhaust pipe. It is visible.

But check the "easy" things first, namely that the 4 wires from that sensor are unharmed and intact, and the connectors are properly joined (not easy connectors to reach, at the rear of the engine below the windshield wiper housing).

+1 Ross, you noticed different banks, P0430 is from Bank 2.

The exhaust pipes combine into one, and then split into two again. Maybe one path is blocked by rust, or maybe there is a gap in the pipe along the way. I believe if this happened after the join (along the tailpipes) there would not be a serious effect. There was a thread recently on this subject but I couldn't find it in a quick scan, sorry. The poster found debris inside the tailpipe as I recall.

bump to see if there was resolution for this. I get the same code all the time. I clear the code and about 50 miles later I get it again. Same car as OP.

See page 81 paragraph 1 , page 128 , and Z

http://www.jagrepair.com/images/Training%20Guides/801S%20-%202000.pdf:icon_dance-disco:

Clean the 2 small ground studs on the engine rear firewall

Bosch # 13789 is a connector ready sensor replacement

I had green corrosion on the rear sensors connectors

https://cimg6.ibsrv.net/gimg/www.jag...5c1bda74a9.png


Editing

Thank you!