Need some help with codes

[wackyracer]

Well the car just hasnt been itself just lately, nothing too major just doesnt feel like it should.
Some times at idle it will idle fine then suddenly drop a rew hundred revs and immediately go back up for 10 seconds or so. Doesnt always do it.
Also acceleration seems to be good one day and not so good the other!

The codes i have just pulled are
16795 - secondary air injection system incorrect flow detected
17705 - pressure drop between turbo and throttle valve ( had this before, fiddled around and went for a while!)
16486 - Mass air flow signal too low
17545 - fuel trim : bank 1 ( add) system too rich

Any of these related to each other and other advice?

Also i have a esp problem. have started to get a code 01435 - brake pressure sensor 1. I think this may be the n.s rear brake as seems to get warmer than the others. If you only brake lightly the esp light stays off, but if you brake hard ish then it will come on and stay on, only goes when switch ignition on and off.

sorry for the list guys.... but you are helpful!

 

[wackyracer]

Rset the codes yesterday and drove to worka nd back and again today... thats about 100 miles. and re read the codes. Nothing on the engine side, just the brake one again.

 

[Hairy]

I found Ross-Tech Wiki helpfull when diagnosing the cause of my fault code. Have a read through and see if the different codes have any thing in common.

 

[wackyracer]

Cheers for that!. Yes some of them are related, good news about brakes as it seems that my brake is sticking and that's whats causing the prob. garage recon a good clean up and lube should sort it.
I am going to check the piping on the intake side etc as it seems several of the probs are 'fuel / air related.
I will post my findings!