2004 Mercedes Benz E 500 4MATIC Sedan (211.083) V8-5.0L (113.969)
This the fault code numbers and description , P0131 dont exist , I sent you a list of the fault codes for this car
could it be P0130 or p0135 or P0136 you meant , cause these are O2 sensor code .
and if this code is on , a bad o2 sensor , maxing out the fuel trim will put it in limp mode , now the O2 sensor could be bad , or there is vacuum leak or a fuel leak and sensor reading correctly and u need to fix these issue before code goes away.
this one needs some testing and diagnostic scanner with you so you can tell me some reading
I usual offer a live phone call for something like that for like $15 but you need a scanner so i can be helpful to you if you want me to call you , just let me know
cause If you dont diagnosis correctly you will be just throwing parts at it
If not I can just tell you what are the possible causes on this Q & A session here
Chad ( aka Jhook 1398)