Hi there buddy, I have a 92 ES300 and also failed the CO part emissions test...however, I took it to a mechanic whom my family goes to often, and he did about $200 in service, and claimed he did about $400 on the receipt, afterwards, took the receipt to the emissions testing station (ohio emissions testing, so rules may be different) and they gave me a waiver good for two years. I guess there is a rule that if you spend enough money on the problem and it doesnt get fixed, they waive it? Worked out well for me, maybe you can try the same thing. Good luck!