Are you sure that your scan tool doesn't have a tachometer output? If not, ask your auto parts store whether you can rent a scan tool that reads engine rpms.

Remove the under-hood BACKUP fuse for about 1 minute and then reinsert. You'll loose your radio station presets and the clock setting.

 

Not sure if scan tool has tach output, I'll check the manual...

 

I have the Actron CP9145 OBDII AutoScanner. Does anyone know if this will show engine RPM data?

 

Yes, go to the view live data menu.

Get the user's manual here:

http://www.actron.com/product_detail.php?pid=16150

 

I had no idea my tool could do this...pretty cool.

I turned the CEL out and it went back on today...but only one code (P0420) and not the idle code anymore (??)

I then went to get the car tested for state inspection (North Carolina) and they wouldn't finish the test. They said their computer gave some readiness code and that the vehicle wasn;t ready to be tested. How can I get around this? That is besides fixing everything wrong with the car, I'm kind of in a crunch or time.

 

Given the idle problem you described, I suspect that P0505 will return with more driving. P0420 typically means that the cat is bad (expensive!), although you'll want to rule out an exhaust leak before spending a bundle of money.

Check here for cat prices:

http://www.hondaautomotiveparts.com/

After you reset the ECU, you need to drive the car for a day or so before the ECU will indicate a readiness for testing.

 

I would probably replace the cat myself if I decide I can manage it. I think shops want way more then I can afford right now. Is this a pretty easy fix? I was able to replace the muffler...with headaches, expletives, broken bolts and all.

 

Yeah, replacing the cat is a DIY project, especially if you already have some experience working on the exhaust system. Even with the use of penetrating oil, be prepared to bust some bolts if the system is very rusty.

 

Yea, the bolts are quite rusty. I will use plenty of penetrating oil. Which bolts are the ones to pay particular attention too?

 

Any rusty exhaust-system bolts that require removal.