Intermittent transmission not shifting properly?

Hi,

Are you referring to the transmission when you say slipping? If so, have you checked the fluid level and condition of the transmission fluid?

Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

As far as the P0420, chances are the catalytic converter is bad. However, let's focus on one thing at a time. Let me know which issue you would rather start with.

Take care and I'll watch for your reply.

Joe

The fluid is fine, it's clean, it doesn't do it all the time and when it does you have to pull over cut the van off and start it back up and it's fine.

That's interesting. I say that because if the clutches are worn and causing it to slip, restarting it wouldn't change that. Is the P0420 the only code you ever had? I ask because I'm questioning if there is a code related to the transmission. It sounds like a pressure-related issue. You may want to consider having the can-bus scanned to see if there are codes.

CAN stands for controller area network. Basically, the different computers/modules are tied together via a few wires. This can retrieve codes regardless of the module storing them.

Here is a link showing how it's done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Let me know if this is something you have already done.

Take care,
Joe

Yes, and the only code is p420 which is that cat o2.

Hi,

The P0420 indicates the catalytic converter is operating under the threshold. In most cases, it is the converter and not the O2 sensor.

As far as the slipping, the best thing to do is a line pressure test to confirm there isn't a low-pressure issue resulting in the slipping. There is a pressure control solenoid mounted in the valve body that may be failing.

I attached pics of the sensor I'm referring to.

Let me know.

Joe

See pic below.