160 Thermostat and CA Smog
 

Thinking about installing a 160 thermostat on my 98 986 but a little concerned about smog because it's pre-2000 and still needs to be sniffed.

From research and experience, I know an engine pollutes a lot more when the engine is cold or cooler.

Anyone in CA with a pre-2000 986 and 160 degree thermostat passing smog no problem???

The use of a 160 F thermostat will not impact your emissions for a variety of reasons, including that your DME is more than capable of adjusting the A/F ratio to keep the car in spec. We have installed many of them, and not one car ever failed annual emissions testing because of the lower coolant temps.

That's good news! I assume you're in CA and talking about pre 2000 boxster which still needs the tailpipe sniffer test? Just confirming because CA standards are different. Thanks

CA is not the only state that mandates "sniffers", we have them on the east coast as well, and use a similar test standard.

I understand that but what makes you think the standards are that similar? We all know CA has the most strict emission laws but I can't confirm the sniffer here is more strict than PA. I'm not being a smart ass. Just really want to know before I regret it when it won't pass.

CA doesn't even do sniffer testing for 2000 and up vehicles now.

Either way, I'm just trying to see if anyone in CA has real experience passing a pre-2000 boxster with 160 thermostat.

The fact that the "urban" PA sniffer published test standards mirror CA's. In some east coast states, early cars (pre OBD II) are required to fully pass emissions sniffer testing while on a "rolling road" test (read chassis dyno), later cars run the national I/M Readiness test standard, but are also subjected to tail pipe sniffers in urban areas.

We probably have a couple hundred cars running the 160 stat, none have ever had an emissions issue related to the stat, regardless of what state they were tested in or what standards they were tested against. Your concern is simply a non starter........................

Agree with JFP. Thermostat isnt going to cause any emission testing issues.

Even if you install a 160 degree thermostat the engine will still reach the manufactures specified= engineered operating temp.
The anti polution system goes into closed loop operation well before that specified operating temp.
Closed loop is when the DME/ECU is monitoring and adjusting fuel/air ratios.
Which in turn regulate catalytic converter temperatures.
Which in turn control the three pollutants in the exhaust.

If you car is showing no CEL or pending codes, all systems are test ready, no exhaust leaks.
There is no reason for your car not to pass smog testing.
No matter which state your in or what test method is used.

I was going to answer before my smog test but didn't want to curse myself! I just got back and can tell you my 98 passed with flying colors. HC was 7and 9. The smog tester was a former smog referee so he was thorough even had me pull the engine cover. This is the 3rd successful test with the 160 stat. I live in a small community so was a sniffer test but no dyno required.....yet.

Congrats on the pass! And thanks everyone for the responses.

I'm going with the 160 :)

When they do the smog test here in CA the car runs on a dyno under load, so the engine is operating at really high temperature while the radiator fans are constantly cycling on and off. Therefore it does not matter what kind of thermostat you have, if you had none, you`d get the same results.