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tman4024 09-04-2013 12:51 PM

Performance tune affecting emissions testing?
Does anyone know if the Diablo or custom tunes(like ones from MHP) can cause you to fail emissions inspection?

I failed on "OBD readiness monitor result". Says the OBD system is not ready to be tested. As a result, your vehicle cannot receive a complete emissions test at this time. This is often caused by a disconnected battery or recent repair work.

I haven't disconnected the battery or had any repair work recently. I reinstalled the tune about 3 months ago.

I had a modified exhaust put on in 09 (this is the first time I've gotten an emissions inspection), but this problem seems to be more related to the computer as it hasn't begun the emissions test.

I'm going back to factory tune tonight and going to drive it around for a while before taking it back in on Friday but thought I'd reach out here for any feedback/help beforehand. Thanks!

robpp 09-04-2013 08:25 PM

Re: Performance tune affecting emissions testing?
Need to go back to stock then drive about 50 miles to get it all in ready state

jeepgcoman 09-04-2013 10:27 PM

Re: Performance tune affecting emissions testing?
The performance tune shouldn't adversely affect the emissions test. I run both my Hemi's with the tunes (one with SC tune, the other with DS tune) installed, without issue on emissions tests. Your emission readiness monitors indicate that the various emissions components have been tested and are working properly. Were you told which component is not ready? Without checking, IIRC, there are 8 components that are tested, ranging from catalysts to O2 Sensors and Heaters. If any one (or more) do not show ready, you'll get the results you received.

If you haven't messed with anything (PCM resets, tune changes, recalls, etc.) within the last 50-75 miles, you probably have an issue with one or more of the emission components. Once any changes have been made to the PCM/TCM settings, all readiness monitors are reset and, as robpp said, it'll take a number of miles to get them all into a "ready" state.

If you have less than (IIRC) 80K on your vehicle the emission components should be under factory waranty. If not, it's on your dime. Since yours apparently hasn't even begun to test the components, you may indeed have a PCM/TCM issue. Good luck, and let us know what you find.

tman4024 09-05-2013 11:12 AM

Re: Performance tune affecting emissions testing?
Thanks guys. I reset back to factory last night and will drive it around more tonight. A year or two ago the check engine light came on, dealer looked at it and said there was some kind of TCM/PCM glitch IIRC, not sure if that has anything to do with this.

Results said:
Catalyst monitor: not ready
Catalyst heater monitor: not supported
Evaporative system monitor: ready
Secondary air system monitor: not supported
A/C system monitor: not supported
O2 sensor monitor: not ready
O2 sensor heater monitor: ready
Exhaust gas recirculation (EGR) monitor: ready

Taking it back for a retest tomorrow morning. Will update with more details then.

jeepgcoman 09-06-2013 11:22 AM

Re: Performance tune affecting emissions testing?
Just make sure you drive it quite a bit before you take it in or you'll still get the "not ready" routine. My code reader shows the status of all readiness monitors and it does take quite a bit of driving for some to indicate "ready". Others show "ready" almost immediately.

tman4024 09-06-2013 12:05 PM

Re: Performance tune affecting emissions testing?
Took it in this morning after driving about 50 miles. It passed :)

Does the Diablo Tuner read these codes? Would be nice to know if I'm ok for future inspections. Jeepgcoman what reader do you have?

jeepgcoman 09-06-2013 07:35 PM

Re: Performance tune affecting emissions testing?
The Diablosport Predator doesn't, and I don't know if the newer ones (Trinity/Intune) will show the emissions readiness status.

I've had my reader for quite a few years. I am sure they have something better now. I have an AutoXray, Code Scout 2500. It reads both OBD I and OBD II vehicles. IIRC, I paid ~$200 for it.....maybe 6-8 years ago. Simple to use and does everything I need it to, even on my old Grand Waggie.

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