I went to Advance Auto Parts today to get the codes read because my check engine light came on, on Wednesday. The following codes were read off:

P0441: Evap Emission System Incorrect Purge Flow

P0171: System too lean (cylinder bank no. 1)

P0740: Torque Converter clutch, circuit malfunction

I think I found the vacuum leak but I haven't been able to fix it yet so I'm not sure if it is exactly the problem yet until tomorrow.

• I was wondering if all these codes could be connected?

• Also if the Torque Converter is not linked to the other two codes what is there that I can do to check it to diagnose exactly what it is?

• If my transmission pan gasket is leaking would that also have anything to do with it?

 

the are all separate problems.

P0441 is a leak in the evap hoses. look first at the easy ones under the hood. next go under the truck to the canister and look at those hoses. all of them like to dry rot and split. bad ones - just replace them (one at a time!!! so you don't get them mixed up). not so bad ones - cut off the split end and reconnect.

P0171 - exhaust, as measured by the O2, is too lean. this is likely a leaking plenum gasket.

P0740 - TCC. incorrect wiring, bad solenoid, etc. has nothing to do with leaking gasket.

 

I just rebuilt the top half on my engine about 3,000 miles ago so I do not understand why the plenum gasket would be leaking? There are rusted out holes in my catalytic converter would that cause this problem? I'm pretty sure the O2 sensor is before that but I was just wondering.

Also what are some steps to take to fix the TCC problem to make sure that it is not the TCC itself but maybe the wiring or the solenoid??

 

How Can I test my solenoid to see if it is bad?

 

If you reused or replaced the stock plenum pan with another stock pan, it can still leak. The correct replacement to stop the leak is to replace with a 1/4in thick plate from Hughes Engines, eBay, or the like in addition to replacing the gasket.