89 190E 2.6 you bought the car six months ago and it ran ok you had to tun it over for 5-10min but you would start the car needed a cat so you took it in to get one but the car sat there for 2 months?
It probably just needed an OVP (over voltage protection) relay that directly behind the battery and only cost about 89.00. It's also possible only the 10amp fuse is blow in the OVP. This is especially likely if your ABS light is also on. Exactly the problem I have with my 89 190E 2.6.