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First p0138, now p2195..What's up?

9.1K views 5 replies 2 participants last post by  Enola Gaia  
#1 ·
A few days ago the check engine light came on and it read p0138, bank 1 sensor 2, so I replaced the #2 O2 sensor. When I went to erase the code, it read that there is now an error on P2195, which is bank 1 sensor 1. Is it even possible that both sensors went at the same time, with only 37,000 miles on the truck, or are the electrical gremlins beginning to stalk me? Any ideas?
 
#2 ·
Did you check for any and all codes when you read the P0138? Are you sure the P2195 wasn't already 'there'?

Both codes can be thrown based on electrical values (ohms, voltage) being out of range. So yes - there's a possibility that you have electrical problems.

Both codes could be thrown based on the ECM having a fault.

Because these codes involve the same bank, it's possible for the fault causing one to give the appearance of causing the other. For example ... The P0138 could have been thrown for a short in its circuit, OR for a combination of high voltage output plus target A/F ratio being lean. Code P2195 applies when the A/F sensor (Bank 1 Sensor 1) is 'stuck lean'.

... So there's an outside chance it was Bank 1 Sensor 1 all along.

The two things both sensors have in common are (a) electrical connections and (b) the ECM. I'd check the electricals first. The P0138 could have been tripped by a short circuit in the sensor circuit, not the sensor itself.

Did you check the resistance on the Heated O2 sensor (B1 S2) before replacing it? It might help to check it to ensure the H02 sensor was really bad.
 
#3 ·
I checked for all codes when the light originally came on, and p0138 was the only code that came up. Drove it for a day or two, checked it again to be sure and it was still only p0138. So I drove the truck to get the o2 sensor, put the new sensor in, drove around a little, and when I plugged the obd in at that point it showed the p0138 and p2195 codes.

I haven’t checked the output of the old sensor yet, but will to do it tomorrow if I have time. So far I just jiggled the connectors around to make sure that they were seated right, but haven't checked for continuity yet.

Thanks once again for the info.
 
#4 ·
Oh ... I didn't realize the P0138 was still showing up. Assuming the new H02 sensor was 'good', that definitely seems to point to electrical or ECM problems. :thinking:
 
#5 ·
Well it appears that it WAS bank 1 sensor 1 all along. It tested bad, so I put in a new one a couple of days ago and so far so good. 50+ miles and no codes or pending codes. Only time will tell, but for now I'm glad it didn't end up being electrical or ECM issues.

Thanks for your input Enola.