the question is, if your 735 has EML at all or not. EML - the throttling cable is not existing, there is a motor which drives the throttling valve. If there is a bowden cable, no EML.
If there is EML, light must come on first and then disappear after 2-3 seconds.
Maybe the cat is blocked. Check the distributor and rotor. All other things to check are on my website below and here
http://www.bimmerboard.com/forums/e32
http://www.e38.org/e32/
including wiring diagrams and locations of fuses and relais.