Hey folks,

I had posted previously about the cherry red catalytic converter on my 2000 Discovery. I had an overheated engine (bad water pump) which blew head gaskets and dropped an exhaust valve seat. It did run very smooth with no problems or idiot lights before overheating. I tore the motor down, had the heads overhauled with a complete valve job and new valve seat & exh valve (engine has 110,000 miles). New water pump. Block & heads were checked for cracks & none found. Put it all back together and had a crapped up cat. So I replaced both catalytic converters with the "Y" pipe and all 4 O2 sensors. I had one or two fouled up injectors which caused one cat to turn cherry red. Now I've replaced all the injectors. Vehicle still idles extremely rough, but on a positve note accelerates extremely smooth and drives extremely smooth (no misfire) which it did NOT do before, but when I come to an idle at a stop light it's very rough. I have 8 engine codes (1300 for multiple misfire and then the same individual cylinder misfire codes (0300 series). Any idea what this could be? As I mentioned it runs very smooth when driving, but idles very rough to the point of almost cutting off at times. This is becoming very expensive. I appreciate all the input I've already received! Thanks!! The advice has been very helpful. Plugs & wires are new.

Matt B.