So, my wife’s car won’t pass inspection, and the error was the Catalyst, Evap Sys, O2 Sensor, and Heated O2 reading “not ready”. This is typically due to disconnecting the battery, but I haven’t done that recently. Also, it’s idling really high, and after accelerating, it takes a while after releasing the gas before RPMs drop.
Any ideas what I should check? I’ll be at the space Thurs night for the Woodshop committee meeting if anyone’s available to help 
Actual OBDII and/or Ford powertrain controller codes might be helpful.
They should look like those on this list, like P1415, P1452, P1453 and P1455, all of which pertain to “evap”.
Is this a 2.0 or the 2.5?
Either way, based on the limited info so far, probably a post-cat O2 sensor), clear codes, recheck (after finishing “readiness drive cycle”). I think this due to experience, the fact that “catalyst, heated 02 reading, and O2 sensor” are all related to this, and, also SWAG.
This forum suggests reset and then drive some more.
Always worth a try, eh?
Autozone can probably pull OBDII codes, but I don’t know about Ford specific. OBDII will probably cut it in this case, just guessing.
And yes, they can almost certainly reset it.
I think the 'Space has an OBDII reader, as well, and that would be the way I’d go (if I’m right).
@Brandon_Green would be most certain to know if there is one, and where, so I’m hoping mentioning his handle will invoke a response…
Diagnostic drawer in the auto area
Awesome! I’ve tried one of those before on my 01 Camry but didn’t know what to do with the codes. I’m a YouTube mechanic
Nothing in that report appears to me to need a reset, but rather possibly repair, and driving cycles to complete the self test. The only thing the OBDII would reset is the MIL, which does not show set. The not ready status is usually a result of clearing codes or resetting power to the ECU.
Which OP says has not happened…
Define recently.
You just have to drive it, not fast highway speeds. I would suggest finding a long road where the speed limit is 55 & driving that. I have had many,many, many not ready 's in 2 of my personal vehicles. Recently I had to replace my wife’s battery & get an inspection. We drove to Sanger then east on 455 to 377 then to 380. This gave us enough drive cycles to the computer to be ready.
A few years ago with my Jeep it took me a month or more to get my inspecton due to the not ready. (Specifically the O2 & catalyst) I drove the hell out of it to get the computer to reset. I drove from Lewisville to downtown Dallas then to Sanger & back to Lewisville, still not ready. I did this to where the inspection station guys knew me.
Ooh, good to know. We’ve had the no codes thing before, but that was just after replacing a battery. Driving fixed if easily enough.
Hadn’t replaced the battery in a couple years this time. I disconnected/reconnected the battery Friday before driving it Richardon to Carrollton to Howe to Richardson. I’ll take it by the local Autozone to see if it’s reading codes now. O2 would make sense for the revving thing, right?
Not in my experience.
Usually this is caused by excessive air.
This is usually caused by sticky IAC (idle air control) device (aka isc, or idle speed control, aka ISC motor, etc.), vacuum leaks, or sticky throttle plate (usually something like build up of carbon behind the plate, causing them to not close properly). All this would be subject to testing/scrutiny…
@kbraby and @TBJK make good points, that if the MIL is not on, and the battery was disconnected a few days ago, you may not have driven enough to reset the readiness sensors. Try the procedure I posted before—it’s a PITA, but it’ll do it IF you can find the road to allow it; otherwise, just try to meet each requirement during your commute)
Codes would set the MIL or check engine light. I have also seen when the battery has been disconnected then the “computer” relearn maps & conditions for idle, this may not be the reason for the high idle but is possible. Also as @jast said. I’d clean that stuff & look for vacuum leaks.
Usually air leaks will cause a rough idle, not just high. You will often get fast idle, ramping toward normal while the ECU is learning the engine and sensors, but I’m used to that clearing within the first drive cycle.
How smooth or rough is the idle, at that elevated RPM, and when it settles down as far as it currently goes?
One other thing that could cause fast idle is a failing coolant temperature sensor.
Failing CTS should cause MIL as well…
If I remember correctly aren’t O2 sensors simple to check? I feel like I use to put a volt meter on them and they would generate about 1v if good. If they didn’t I would replace. I had a 96 Sonoma truck that had 4 of them.
@jast gotta admit, not sure what MIL is… Gonna try that reset procedure if I can figure out the ODB2 part
@TBJK gotta admit, not sure how to clean and test for vacuum leaks
@kbraby engine still feels really smooth at high RPMs and at low once it settles down
I’m totally down for checking/cleaning/resetting stuff… Just not sure how beyond what I’ve tried. Any good YouTube resources?
Malfunction Indicator Light (aka “check engine light”)
If I were a better-trained 'Mercun car technician, I would better use OBDII acronyms, and instead of CTS for “coolant temperature sensor” I would have called it “ECT” for “engine coolant temperature” sensor, but at least I used MIL correctly!
At its most rudimentary, yes, you can simply check to see if the O2 sensor (O2S) makes voltage when heated. A DVOM is nice for checking heater voltage and circuits, as in these videos: eric the car guy checks a 4-wire on a Honda; checking an older 3-wire HO2S on a 1997 Nissan Maxima .
However.
In order to check ACTUAL function of the O2 sensors you really need a 'scope. Here is a decent article with some pictures related to O2S functions and catalytic converter function. Note the pre-cat O2S should cycle nicely, roughly a sine wave, while the post-cat should be roughly steady. (The pre-cat measures oxygen levels in the exhaust, and the ECU uses this to adjust the fuel, cycling between lean and rich, always trying to reach “perfect combustion”. The post-cat O2S is used to measure catalytic converter efficiency, meaning there should be a steady supply of oxygen coming out of the catalytic converter, indicating completely spent fuel supply.) Some scanners allow you to check these measurements (at the ecu) through the OBDII interface. Some do not. I know nothing of the one at the 'space.
All of this may be unnecessary, though, as @kbraby noted, since the MIL is off, and the battery was disconnected recently (4 days definitely counts as recent). Again, some scanners can assist in setting readiness codes. I don’t know about the one at the 'space. The way around this is try this procedure (to the best of your ability, until it works). Then worry about the idle issues, if they haven’t settled down on their own.
If you need a scope in automotive (perhaps auto should buy one) please don’t remove the Rigol from the Electronics room. That scope is labeled that it isn’t supposed to leave the Electronics room (except for approved classes).
We have plenty of analog scopes and one inexpensive digital scope that would be better suited to the rough environment around cars.
@artg_dms
I’d suggest a “smoke test” for un-metered air. A good friend has such a specialized tool and would be willing to do a show and tell on a weekend…
a “scan” does not always produce trouble codes - sometimes one actually has to do some old fashioned troubleshooting (not something today’s dealer techs are very good at)
Also keep in mind that if you disconnect the O2 sensors & try to run it you will likely get a MIL. I personally would just drive it for a bit. The not ready’s will clear up & either give you a fault or run just fine.
