CEL: P0138 and Pending P0138
Thread Starter
|
Junior Member
Joined: Jul 2010
Posts: 20
CEL: P0138 and Pending P0138
I have a 03 civic DX with a 02 EX engine and ecu in it.
Recently the p0138 code popped up with a pending p0138. the code means the the downstream o2 sensor is giving off a high voltage signal (post cat rich condition) meaning the cat is bad or the sensor is bad. I replaced the sensor with one from Honda since i had a cheap aftermarket sensor in there. CEL came back on during second start up after highway driving. freeze frame showed this happening at 50mph, so i thought it would have to be the cat. To make sure that cat was in fact bad i made a mechanical o2 sensor simulator out of two spark plug non-foulers but that did not keep the code from coming back.
Anyone have any ideas on what could be the problem and how to diagnose it? Thank you in advance.
Recently the p0138 code popped up with a pending p0138. the code means the the downstream o2 sensor is giving off a high voltage signal (post cat rich condition) meaning the cat is bad or the sensor is bad. I replaced the sensor with one from Honda since i had a cheap aftermarket sensor in there. CEL came back on during second start up after highway driving. freeze frame showed this happening at 50mph, so i thought it would have to be the cat. To make sure that cat was in fact bad i made a mechanical o2 sensor simulator out of two spark plug non-foulers but that did not keep the code from coming back.
Anyone have any ideas on what could be the problem and how to diagnose it? Thank you in advance.
Thread
Thread Starter
Forum
Replies
Last Post
JAB1986
Mechanical Problems & Technical Chat
19
Mar 10, 2012 07:33 PM
fongcom
Mechanical Problems & Technical Chat
0
Feb 9, 2011 03:02 AM
Jaredarchuleta5
New Member Introductions
0
Jan 9, 2011 08:22 PM
gristle
Mechanical Problems & Technical Chat
8
Feb 19, 2009 06:58 PM
