P0243 code: Post Transducer swap questions
 

Got the P0243 code on my 1998 E300D about 2 weeks ago. At first the car still ran fine, later lost some power. I searched this forum so I knew some of the suggested fixes. Went by the repair shop who checked with his computer than told me I needed to replace both the turbo wastegate and EGR transducers. I did not like his suggestion. Seems he just want to find the fastest fix with the highest chance of success, but at the cost of me footing unnecessary repair bills.

So I did the transducer swap myself, it was indeed easy after getting the instructions posted by the members here (and thanks to TMAllison and others). So far the code has not re-appeared and the car is driving fine.

So it appears the turbo waste gate transducer is bad. As I understand it, the EGR system is more tolerant of a bad transducer so I can get by for now. Have the following questions :

!) For people who did the transducer swap: how long before you experienced problem on the EGR system and what is the OBDII code for EGR malfunction?

2) Should I go ahead and replace the bad transducer now?

3) I searched fastlane could not find the transducer. What is that parts number and where is the best place to buy the transducer?

Sounds like you solved the problem. No codes....Whats left to fix?

Sounds like a case of Post Transducer Swap Stress Disorder or PTSSD , a bit like PTSD or ADHD. :D

I was thinking that since the swap solved the problem, the transducer going bad must now be on the EGR side -so sooner or later the EGR malfunction code will show up. I am about to take a trip, so I am concerned that the problem may come up while I am on the road.

In technical terms, the transducers can get some "schmutz" inside them which can make them less responsive than they need to be. I have opened them up and seen it firsthand (though I don't recommend doing this because it is a one-way trip to the trashcan) .

If the OP wants to be proactive he can order a new one and replace the one on the EGR (which he swapped from the wastegate actuator) or just drive and not worry about it until the EGR throws a code, which may never happen. You won't do any harm driving as it is if the system isn't throwing a CEL.

A better thing to do than spend the money on a new transducer is replace the two little vent filters on the ends of the vent lines...those are what let the schmutz in and can cause CEL's on their own if they have any resistance to flow at all. They run about $10 a piece but should be replaced every 5 years or so.

Thanks nhdoc for the suggestion.

Is there a part number for the vent filters, I can't find the part on fastlane. Also, noticed the vent filter is held down by plastic tie which I assume must be cut to remove the filter. Is there a part number for the plastic tie?

AFAIK those filters are dealer items, and they will likely have to order them. The PN is 000 078 09 56. As for the ties, yes, cut them and just use generic zip-ties to replace them and it will be fine or, I am sure the dealer can order you special M-B ties at 10X the cost - those are PN 004 997 98 90.

IIRC the last time I ordered the filters they actually came with the ties.

Good luck!