I've put a ton of miles on the car since I replaced the battery but both EVAP and O2 still read Not Ready on my OBD2 reader. I need at least 1 to run in order to pass the emissions test. Any ideas on why they might not be running? I have never had to make a car pass SMOG before so I'm new to all of this.

1997 Lexus SC400

I do get 2 pending codes - both EVAP - so I assume that's why the EVAP system is not ready but why won't the O2 sensors run their check?

 

Has anyone ever heard of a problem with this system that will not allow a monitor to finish its drive cycle? I'm trying to figure out what to do. No matter what I do driving wise I cannot get the O2 monitor to ready status. It does not throw any codes - no pending and no faults but they won't pass me with it set as not ready.

No idea what to do. I even broke down and called a diagnostics shop. The guy there also did not know what to do.

Help?

 

The only time I've seen that type of failure is with a bad or weak O2 sensor, bad wiring to the O2 sensor or someone running an aftermarket engine management system where the tune messed it up.


If you're not running an aftermarket engine management system and you haven't been messing around with the wiring harness, you more than likely you have a bad or weak O2 sensor that needs to be replaced. They can go "weak" but not so bad that it will actually throw a check engine light or CEL code on your OBD II scan tool, so don't let that mess you up. They can be tested if you have the proper tools (most people don't) but by the time you pay for diagnostics you could have probably just bought two new ones and replaced them.

 

Ok cool thanks for the answer. The P/S pump was shot when I bought it and had leaked all over the passenger side internals. While I was down working on the EVAP system I noticed the bank 2 sensor 1 was pretty soaked in fluids. I might try replacing that if I can't make any forward progress on this pending code in the next couple of days.

 

Looks like two threads got merged together or I would have asked this earlier, but what are the EVAP codes your getting?

 

Not at home right now but pretty sure I was running PO144 pending. I tracked down that problem though. There was a good sized hole in the charcoal canister. I actually just taped it up and that solved the problem - Passed smog yesterday. Now I will never have to test the car again!