Passed Smog!

Yippee! Was my first smog test for my XJ. Wasnt sure how I would do.

most 4.0's actually do pretty well. Thats where our hot running engines help us out.

I need to smog mine soon. It should be interesting to see how that goes...

sintax said:

most 4.0's actually do pretty well. Thats where our hot running engines help us out.

I need to smog mine soon. It should be interesting to see how that goes...

Click to expand...

Interesting you should say that - I noticed a decrease in HC and CO when I pushed my operating temperature down about 10-15*F. Everyone told me it would be a problem for the Air Police, but I hadn't noticed. See my recent Air Police rant for more information about what I think of them...

5-90 said:

Interesting you should say that - I noticed a decrease in HC and CO when I pushed my operating temperature down about 10-15*F. Everyone told me it would be a problem for the Air Police, but I hadn't noticed. See my recent Air Police rant for more information about what I think of them...

Click to expand...

hmm I was always told a hotter engine would do better. *shrug*

sintax said:

hmm I was always told a hotter engine would do better. *shrug*

Click to expand...

I am sure Rollins can chime in but I thought I heard an engine that is a little on the 'hot' side can suffer from higher NOX especially without the EGR. :dunno:

I had to put a new cat on my YJ ($150), I guess hey dont accept "test" pipes. Thats one thing we cant pillage at the junk yard anymore.

Do you guys think I'll pass with the rustys 6x9 filter, with a bored tb and spacer?

I saved my old stuff, just because I can't through anything away.

Correct. NOx is caused by elevated temperatures in the combustion chamber, leading to a "burning" of the nitrogen in the air and the formation of NOx.

The EGR is meant to reduce NOx, but it does so at the expense of increased HC and CO emissions (due to incompleat combustion.) My XJ actually runs cleaner withouth the EGR than with it, but I won't pass if I take it off and block it (because it's an unauthorised mod.) Likewise, if I roll in with the thing disconnected at the vacuum line, I'll get docked something like $200 for "disabling emissions control devices," or somesuch nonsense.

Result? I disconnect the thing except for when I need to get a smog check every alternate year. Disconnecting the EGR reduces HC and CO, lowering the operating temperature slightly has a positive impact on NOx formation, and I get slightly better fuel economy anyhow.

The only smog device that is intrinsically useful is the PCV/CCV system - apart from that, adding emissions control devices results in a balancing act between the various devices, since they all operate on a "trade-off," improving one aspect while worsening another.

Honestly, one could literally remove all the "emissions controls" save the crankcase ventilation and tune your engine to reduce emissions while eliminating a number of "potential points of failure." Keep the engine in tune once done, and you've got emissions reduction (if not quantifiably eliminated outright,) increased fuel economy, and lowered total cost of ownership (due to fewer specialised parts to fail.) Now, if we can just convince EPA and CalEPA of this, we'd be getting somewhere.

As I recall, when I got my 87, the first smog check I had to do afterward was with a failed EGR (I found out because the guy fingered my vacuum lines - after I crossed out the part that authorised him to...) Emissions? HC and CO was unmeasurable, and NOx was down around 10-15ppm.

I put the EGR on, and HC and CO jumped, while NOx remained virtually unchanged. Y'ask me, that was just throwing $150 down the commode...

Thank you John for clearing that up

Just comes from doing a little research.

It's nice having access to SAE books through the city Library...

indeed that was a good read.

I've hear that a homemade custom intake tube/filter assembly on my 95 OBDI jeep would not cause me to fail the visual part of the inspection, because that stuff is all ahead of any emissions controlling device. Anyone know if that is true? I hope so, cause I really don't feel like putting all the stock stuff back on just to pass smog.

Kyung

Bottom line if anything is added and you do not have a CARB exemption sticker they can fail you on the visual inspection. Not all places might though, best to ask. I always do a pre-test prior to smogging my Jeep that way I can fix what it needs.

MJR said:

Bottom line if anything is added and you do not have a CARB exemption sticker they can fail you on the visual inspection. Not all places might though, best to ask. I always do a pre-test prior to smogging my Jeep that way I can fix what it needs.

Click to expand...

Pretest is always a good idea.

Thanks,

Kyung

MJR said:

Bottom line if anything is added and you do not have a CARB exemption sticker they can fail you on the visual inspection. Not all places might though, best to ask. I always do a pre-test prior to smogging my Jeep that way I can fix what it needs.

Click to expand...

Exactly.

Any CARB "approved" part will have an Executive Order number, and there will be a small sticker (either on the part, or loose that you stick on the part or next to your underhood emissions tag) carrying the EO# and a short description of the part. No EO#? Instant failure on visual - doesn't matter how good the "sniffer" test is.

AFU, but that's the way it are, and that's what we're going to stay stuck with, until we get enough people agitiating for a change. The programme could be better - but it won't be, until enough of us get together and start making noise. The expect it from SEMA - we need a groundswell...

x3.

The place I took it to said that if I didnt have the CARB approved MFr sticker for the K&N FIJK, then it would have failed. So go find a sticker somewhere....

PASSED!!!! I didn't do a thing. No CARB stickers, custom intake, wj manifold, larger throttle body(which the guy pointed out as not stock). I'm happy.

Kyung

I'm down here in SoCal now and may be down here for a while it all depends where I land a job. I am not ever going to move my registration for my XJ out of Humboldt because in that part of California no smog is required. Well I would only have to smog it if I sold it.

corbinafly said:

PASSED!!!! I didn't do a thing. No CARB stickers, custom intake, wj manifold, larger throttle body(which the guy pointed out as not stock). I'm happy.

Kyung

Click to expand...

Sweet! lucky too

hey Kyung did u take it to the San Pedro place?