[Spyro235]

All: only one thread really seems to come up with a google on my codes.

Mine are as follows: 0046CF Reducing agent valve, control
004BAB Reductant tank active fullstandssensor, Signal
0047E9 Reducing Agent Foerderpumpe, control
004A2E Glow plug cylinder 5, control

My truck has 206k miles on it now, so it's not surprising that some of these systems are starting to head out. I assume the glow plug just simply needs replacing- when it's super cold, the car runs a bit rough and seems to miss on 1 cylinder, which I presume is #5. it never misses under load after warming up a bit.

As for the other three codes: is it less expensive for me to go for the "VW tank" fix? I'm capable of performing it myself, but I'm unsure of if I really want to keep the systems. I'd love to get a tune, and am fine with a "stage 1" tune that simply turns off the EGR, and still runs the SCR and the DPF. EGR off gains a few mpg from what I've read, and if inexpensive, I'd like to continue to have relatively clean air coming out of my exhaust.

I've been doing research, and asking questions about deletes, but if I could keep these systems running for cheaper, it might be the move for me.

[PerfectAce]

I'm not sure about the tank issues, but I would bet that your glow plug code is related to the controller and not the actual glow plug itself. Check you coolant temperature once your vehicle is fully warmed up -- it should be around 88 deg C. If it's much lower than that, it indicates that your thermostat has (partially) failed in the open position. Low coolant temps seem to inevitably lead to burned out glow plug controllers.

[Spyro235]

My thermostat JUST went this past weekend I believe. Noticed a bout of awful mileage, and checked my coolant temp: 59-65C. Thermostat is being swapped now.

[dmanb2b]

Originally Posted by Spyro235

As for the other three codes: is it less expensive for me to go for the "VW tank" fix? I'm capable of performing it myself, but I'm unsure of if I really want to keep the systems. I'd love to get a tune, and am fine with a "stage 1" tune that simply turns off the EGR, and still runs the SCR and the DPF. EGR off gains a few mpg from what I've read, and if inexpensive, I'd like to continue to have relatively clean air coming out of my exhaust.

Tuner can also leave just the dpf functioning...ex. turn off egr and scr