I have a 2000 Disc 2 with 174,000 miles new O2 sensors. But I’m now getting three new codes P0446, 0327 and code 1174 does anyone have a clue where I should start .
I put in new plug wires and plugs and coil pack in Oct last year. And I only use 91 or better octane gas. The check engine light only comes on when I’m at idle

 

This is the frist time that I have ever posted anything so I have not done the best job of it. I did post this the other day and Dico Make's reply was the 446 is a vent control issue with the Evap system, the 327 is a bank 1 knock sensor and the 1174 is a rich run on both heads.
When was it last tuned along with plug wires, what octane gas are you running?

 

I have replaced the gas cap that seems to have taken care of two of the codes but still getting code P0446. Any one have any ideas? Thanks