CEL for low temp cat P1426 and P0427

I have no thermocouples for last 4 years but I am getting CEL recently telling me the CAT is too cold. CEL code is P1426 and P0427.

 

Why I am getting CEL now? What can I do to get rid of it?

 

My junctionbox is the revised style. I plan to disconnect it to see if CEL returns.

 

BTW, I do have two similar brake-line looking metal tubes attached to FRONT of the cats. Are these misfire tubes?

 

I have no thermocouples for last 4 years but I am getting CEL recently telling me the CAT is too cold. CEL code is P1426 and P0427.

 

Why I am getting CEL now? What can I do to get rid of it?

 

My junctionbox is the revised style. I plan to disconnect it to see if CEL returns.

 

BTW, I do have two similar brake-line looking metal tubes attached to FRONT of the cats. Are these misfire tubes?

 

 

I would REALLY looking into the CAT temp ECU. If you are only getting a CEL that one CAT is too cold then swap the inputs to the CAT temp ECU and see if the code hops to the other bank. If that's the case then it's the ECU. Easy fix and relatively inexpensive. I had the same problem just a few weeks back.

Hope that's helps.

 

Thanks! Can't swap them as the connectors are different on the newer style junction box. I did get a healthy reading from the thermocouples with 14.5 and 16mv that increased as car heated up. Will drive around more to see if cel returns.

Thanks! Can't swap them as the connectors are different on the newer style junction box. I did get a healthy reading from the thermocouples with 14.5 and 16mv that increased as car heated up. Will drive around more to see if cel returns.

 

Not the junction box. The Cat temp ECU

i see. where is that?

The junction block is the cat temp ECU also called cold thermal joint it goes by many names. Have seen this on many Gallardos 8 out of 10 times its what is going bad. It can be very intermittent.

 

Yes those are the misfire tubes. They go to a sensor just above the bell housing in center before the engine valley.

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The junction block is the cat temp ECU also called cold thermal joint it goes by many names. Have seen this on many Gallardos 8 out of 10 times its what is going bad. It can be very intermittent.

 

Yes those are the misfire tubes. They go to a sensor just above the bell housing in center before the engine valley.

 

Thanks!!

I put everything back and was able to slightly tighten the thermocouple sensor on the cat. CEL hasn't returned after 2 drives with about 100 miles. Lots of labor but at least the issue is resolved.

 

On G with the newer style junction box, I think the codes are a result of loose thermocouple sensors. On G with the older style junction box, it's likely the junction box if you have corrosion.

 

Of course, it could also be the car sitting for 2 months. Gotta drive it more!