2004 xc90 t6 - p0420
#1
2004 xc90 t6 - p0420
I am getting a P0420 code, inefficient cat, I have replaced the o2 sensors (all three - aftermarket brand) - replaced most of the vacuum lines and ran cat-cleaner through the system.
the last thing to do is directly test/replace the cat. I have a hard time believing that the cat is actually bad - but the car does have 160k miles on it, so it is conceivable.
BUT I wanted to exhaust all other options first. I can see the test the ECM fails, which is "Rich to Lean Sensor threshold voltage (constant). Max: 51 Current: 104" which, I assume is triggering the OBD code
Anyone have any thoughts?
the last thing to do is directly test/replace the cat. I have a hard time believing that the cat is actually bad - but the car does have 160k miles on it, so it is conceivable.
BUT I wanted to exhaust all other options first. I can see the test the ECM fails, which is "Rich to Lean Sensor threshold voltage (constant). Max: 51 Current: 104" which, I assume is triggering the OBD code
Anyone have any thoughts?
#2
#3
Updates - Solutions
Thanks everyone, you all have been very helpful. I actually did have the code come back, so I went back to the standard troubleshooting steps:
Easy/Cheap Problems -> Harder/Expensive Problems.
So starting again with the Vacuum Lines, I actually found a leak I had overlooked.
The Vacuum change over switch! I noticed when a little starter fluid was sprayed on it, the engine would react - pretty obvious v. leak. (it was/is sort of tucked under the fuse box so I can see how I missed it the first dozen times)
So, I did a quick fix (glued the **** out of it, ensuring that the brakes were still functional) and ordered a new one. Drove 1200 miles, at various speeds, and the CEL came back. BUUUT with a new code (a VERY good thing) - massive vacuum leak in the evap system. So new gas cap (the most likely culprit) and so far, so good. I'm glad I did all the other fixes, since they were things that needed addressed, and it looks like I'm good to go (passed smog the other day too - so the CAT is fine)
Anyway, hope that helps someone down the line.
-A
----------------------------
2004 XC90 T6
1997 Mercedes S420
Easy/Cheap Problems -> Harder/Expensive Problems.
So starting again with the Vacuum Lines, I actually found a leak I had overlooked.
The Vacuum change over switch! I noticed when a little starter fluid was sprayed on it, the engine would react - pretty obvious v. leak. (it was/is sort of tucked under the fuse box so I can see how I missed it the first dozen times)
So, I did a quick fix (glued the **** out of it, ensuring that the brakes were still functional) and ordered a new one. Drove 1200 miles, at various speeds, and the CEL came back. BUUUT with a new code (a VERY good thing) - massive vacuum leak in the evap system. So new gas cap (the most likely culprit) and so far, so good. I'm glad I did all the other fixes, since they were things that needed addressed, and it looks like I'm good to go (passed smog the other day too - so the CAT is fine)
Anyway, hope that helps someone down the line.
-A
----------------------------
2004 XC90 T6
1997 Mercedes S420
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