As with all cars, there comes a time for regular maintenance.  Tune up parts for Mercedes are notorious for being over priced and the local stealerships don't help matters much.  I picked up OE Bosch plugs at the local auto parts store for about $2 each and increased the gap to .042.  The cap and rotor were a different story though





I wont even go into how much the stealership wants for a OE distributor cap and rotor, but the local auto parts store wanted $170 for a Bosch distributor cap.  I picked up a OE Bosch cap and rotor off of Ebay for under $100, unused.  Pays to shop around.





While in the process of removing the OE distributor cap, the thing crumbled in my hands, must of been pretty old






New cap installed and ready for the spark plugs and cap cover to be put back on.  This tune up is rather easy and all that is required is a hex head (forgot the size, sorry) to remove the distributor cap.


Although I don't have any pictures of this, the O2 sensor is a three wire Bosch unit that the dealer wants over $200 for.  After some careful research, I found that the 1990 Ford Mustang 5.0 uses the exact Bosch 3 wire O2 sensor, but with a different plug on the end.  I bought the Mustang O2 sensor for $36 and cut the plug off my old O2 sensor and spliced it onto the new O2 sensor.  Works perfect!