i have a similar problem to this,i have a 99 rex and the CEL comes up occasionly and only when going up hills, rms has told me the oxygen sensor on exhaust is fuked and is whats causing this, would it be worth forking out the few hundred to replace it or should i just pull it out all together? i also get the jumpy starts on a cold engine. and ebay has shown no sensors for cars before 2003 =(