Car - 97 E420 106,000 miles


Past owner used mineral oil for 9 years, but I'm switching to Mobil1. I must assume there is a some sludge & buildup, and also switching to Mobil1 w/ high detergent level will break things loose. Therefore is it advisable to use a engine flush and/or engine cleaner (www.auto-Rx.com?) before switching to Mobil1? I will also use a bottle of Techron fuel cleaner.

Car gave P0172 (too rich bank#1) code a few months ago, and the spark plugs and connectors were replaced. However the car has an unstable idle and rpm drops periodically. I also have the dreaded ticking noise. I want to start w/ most simple solutions first before moving on to MAF, injectors, coil packs etc.

Thanks for help.