I have a 2001 S4 and about every 2 days they car will not start unless I use starting fluid on it. The only code that I get out of it is P0455/16839. I have the Ross tech to scan it but everything I have seen says the 16839 code shouldn't keep it from starting. Help please.

Edit: fuel pump is new and relay is good

 

when i got this code it ended up being a bad seal on my gas cap. i didint have the no start issue though. i'm thinking you have a huge leak in your gas line/evap system and are losing fuel pressure causing the car to not start. check your injector seals, gas lid and evap canister purge valve.

i dont have to much experience with this issue. i hope this helps.

 

Thanks I'll check that. Is there no way to see fuel pressure with the Ross tech?

 

you can log it with vag-com, and compare the requested fuel and actual fuel to see if they vary alot.

im not sure if vag com can actually read fuel pressure though.

post up here as well:
B5 S4/RS4

im like the only b5 s4 guy left on here. audizine has much more support.