I have this 92 Roadmaster that about a year ago started running rough, miss firing and bogging down during acceleration. The service engine light came on and the code it gave was 44, oxygen sensor reading lean exhaust. Now after it runs for a while and we shut it off for more than 15 minutes it takes about 10 minutes of cranking the engine over in short bursts to get it to fire at all. Then to keep it running you need to rev the engine to 4000 rpm for a second or two to keep it running.
Help please.