A couple years ago, I switched my thermostat to a 180, because the old one apparently gave up the ghost. (I now realize it was only the bad gasket.) As expected, I got the Check Engine light as a result, but pulling out the correct fuse would reset it... no big deal.
Well, I went to take my car for inspection and my guy said, "It didn't pass the state emissions test. Did you reset something?" I said, "Yeah, because I have a 180 degree thermostat."
"Yeah, well the emissions computer knows that there's no memory in the computer and won't let it pass. If you had told me, I would have known to look for that."
So I bought a 202 thermostat so I won't get the error code anymore (I never noticed any difference with the 180, other than that my gas mileage seemed to suffer), but should I know anything before I install this? I mean, is there a way to get the car to pass without all the trouble? (Now that I know that it was just a gasket, I'm mad that I threw out the old thermostat. Duh!)
I searched the forum for questions like mine (I actually used to be a member, but the system wouldn't let me log on with my old username, even though I still get updates to my email from the Challenger forum), so I'm sorry if the question seems stupid.
ChrisGee... first let me say WELCOME (or welcome back) from our West Virginia LXs in the Mid-Ohio River Valley. Please consider posting and intro thread in our new members forum so that more people will recognize that you've come to 3CF.
If you got a CEL after installing the 180 Tstat it was undoubtedly for Tstat Rationale, i.e., the coolant didn't reach 180 F in the appropriate time. This is easy to overcome (and I find it necessary any time the ambient temperature is below 55-60 F) by running in autostick (defeats MDS) until the engine reaches the target temperature. What that has to do with "the emissions computer knows that there's no memory in the computer and won't let it pass" - I have no idea. I would think there is no connection to the Tstat. Further, you said you did this several years ago... yet it passed emission inspections in previous years?
Also I've run a 180 Tstat in both vehicle for several years now, and have seen no impact at all to fuel economy, so I don't know where you're coming from in that regard.
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Once you pull fuse 11 or do a battery disconect the car MUST be driven thru 4 to 5 full warm up cycles totaling about 75 to 100 miles to RESET THE OBD-II readiness moniters before the car can pass an emission test. OBD-II readiness moniters include a egr test, o2 test, cat test, gas tank vent leak test, computor and elec componant test. Pulling fuse 11 resets these tests and they must be returned to good values in the computor memory only by driving the car a few days and then reschedule the emission test
i was going to say you have to drive alot of miles before it actually "resets", or in my case before it CEL kept coming on haha
Anyways good luck and remember if your running a 180 to also change your fan speeds
Should I be concerned that my vehicle will not pass the emissions test if I install a 180 degree t-stat? I don't want to have to put the original one back in to go for emissions testing. Have any other members had problems like this? If it throws a code, can't I just use the Predator to clear it? Why would it need to be driven around for a while to clear the problem?
Ken apparently some cars throw codes some don't. Depends on the number of key cycles where it does not reach a satisfactory temp, I believe it is 170 +/-. I am sure someone here knows the magic temp and can chime in. I use the 185 degree tstat because it is so cold here in the winter and I don't want to mess with it. But, that said I have not seen any codes on mine. I know in the real cold times running it to the bus station just a mile away and local errands do not warm it up very much for a few cycles, but I must not have hit that unlucky number. You are right, just clear the code with the Predator. I think someone thought they needed to put some miles on the car after a reset to pass the test. I think you need more key cycles. We are happy about one thing in MN...no tests!
Sometimes the temps get to the high 180's and I know I may be on the edge of heat soak, but that is the happy medium I probably need to live with.
While I have not had a problem with passing the emissions testing I did have the occasional CEL for the P0128 DTC. I would just clear it with the Predator. Then I thought I could do something to prevent the code from setting to begin with.
Last December I posted the following in response to someone else's problem with the P0128 code: "For what it's worth, this year I whipped up a 23" long by 12" wide piece of trash bag duct taped to a steel rod along the 23" edge, and suspended it behind and below the power steering cooler and infront of the radiator from the bracing that spans between the radiator crossmember and the backside of the grill with a couple of strands of wire.
The completed assembly looks like this:
It works for me! The only problem is the white duct tape is visible through the grill. I'll fix that next winter season.
Yes that would heat it up faster but i'd rather my car breathe and be more sufficient.
The fans speeds are 185 for low fan settings and 192 or 193 i believe for mid and high fans, i can double check if you'd like.
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