what is the specs. on a egr valve for a 1998 mercedes benz?

[Diego]

i changed the egr valve on my mercedes benz ml320 so i can pass the smog test...i reseted it and drove it for more than a mile, light came on...the same code (p0400) popped up again....i took it to a mechanic and he told me that theres normally some kind of number on the original egr valve that tells you the specs, or the pressure or something like that, so when putting in the aftermarket one you know what seal or washer or pressure to use.well i dont know what number it is because i threw it away like a dumb ass,(honestly i can be explaining it wrong, hope someone understands what im talking about) when i bought the part from car quest it didnt come with anything other than the egr valve, i assumed thats all i needed, but was told seals, or washers are supposed to come with it (im not a mechanic or a good one at least)......any suggestions please......

 

[fasttoysmullen]

I dont think your problem is the EGR valve. It is either the vacuum system or electrical system that runs it. I am not familiar specifically with MBZ however what is the definition of that code. Is it low flow or high flow or no flow of the egr system. No flow or low flow could be clogger egr passage, broken vacuum line to the egr or the vacuuum relay (if equiped) which is electronically controlled, could be bad. If it is a back pressure system, that is used to ck egr flow, that sensor could be bad. There are so many times you get a code for a specific part and the part is ok but is the system within that part that either operates it or checks it operation is actually the failure. You could actually save money by taking it to an independent MBZ shop before you change 10 more parts out costing you hundreds of dollars and still not fixing it.