So here is my question kind of specific. My TJ is a 1999 4.0 so technically according to the VIN it has 1 downpipe, 1 cat and federal emissions standard. Butttt my actual motor is a donor motor from a 2000 therefore it has 2 down pipes and 3 cats. So my question is will emissions be based on 99 or 2000. I need to replace the dual cats on the downpipe and there is big price difference between CARB and non-CARB compliant cats…
Newer engine emissions
- Thread starter Dh2002
- Start date
The emissions will be based on the year of your vehicle. Just make sure you keep your factory PCM and wiring, as one from the later models would be expecting 4 O2 sensors as oppose to 2.
So basically, to make this work best, keep the wiring harness and PCM from your existing engine, just swap in engine from the 2000 and nothing more.
So basically, to make this work best, keep the wiring harness and PCM from your existing engine, just swap in engine from the 2000 and nothing more.
Not sure what the NYC emissions rules are when putting a newer model year engine in an older model year vehicle, but in SoCal IF all the emissions parts connect from the older engine to the newer engine and the engine passes tail pipe emissions on a dyno ('99 is the last model year that needs a dyno test) you are good as long as the inspection station doesn't know its a different engine model year. IF they some how determine the engine is from a newer model year; you will probably need to go to a referee station to sign off the swap....
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The EPA requires all emission control devices including EVAP from the newer engine are included with the swap. That's the law but nobody except CA really gives a shit about the law. Just make it look like a 1999 and NY will be happy.
Yeah.... California are the Emissions Nazi's....
2000 model year 4.0 came in 2 configurations CA and FED emissions. The CA has 3 cats and 4 O2 sensors, the FED comes with the same style exhaust manifold and Y style exhaust as the CA, but it does not have the pre-cats and it only uses 2 sensors. One bung is in the lower end of the head pipe, and the other bung is located after the cat.
The Y section is pretty inexpensive to replace, @ $200. I'm not 100% sure but I believe the below pictured head pipe would bolt up to the 99 cat without any modification.
The Y section is pretty inexpensive to replace, @ $200. I'm not 100% sure but I believe the below pictured head pipe would bolt up to the 99 cat without any modification.
You never did reply to @Lou as to which wiring harness you intend to use.
If you intend on using your original harness and pcm, why not just swap your engine externals over to the 2000 long block.
If you got and are using the harness and pcm for the 2000 and the exhaust came with the 2 pre-cats the pcm should be set up for CA emission and if so it wouldn't work with the 2000 FED exhaust set up or either of the 99 configurations without being reprogrammed.
Edit: that is all assuming you still have the original engine and PCM in your possession.
Ok so in that case you are working with a CARB compliant 2000 engine and PCM. As I said before the difference between FED and CA on the 2000 model year was the pre-cats and the 4 (CA) vs 2 FED) o2 sensors.
I have personally never had to deal with emissions testing but I have worked in auto repair shops doing pretest maintenance. If they run the OBD test you will have to be 2000 CARB compliant, because those tests are based off of what the computer sees.
Rubicon John
TJ Enthusiast
In Atlanta they scan the vehicle. If you have 6 out of 7 monitors pass readiness with no codes you pass emissions. I honestly think this question is state dependent.
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