Hows it going?

I have a 2001 CL with 180,000 miles on it. Being at school I rarely have time to work on my car. I have been dealing with a check engine light code for a bad O2 sensor. I just changed the o2 sensor and had the check engine light reset. I drove it for about 20 miles and received the new p740 code. I have recently changed spark plugs also, I dont know if that has anything to do with either of these issues. The car has been sitting for 8 months so I also dont know if that could have something to do with it. Im away at school and only have a small amount of time to work on the car. HELP! I need to pass inspection!

 

I may be wrong but the P740 code isn't for a bad O2 Sensor. P740 is a code for transmission or torque converter issues.

 

Yeah I had a different code I believe it was P420 for the o2 sensor. That was the only code for months. After not driving it for 8 months or so the new p740 code came up.

 

I would check your transmission fluid from the start. Does the cl shift OK?