Ca smog readings for 4.0 H.O.

After spending a few weeks screwing around on the smog dyno at work I finally got my NOX down..way down.. for the full ASM diag test on our smog dyno. nox down to 7ppm during our testing..averages for complete test 230ppm.. way below the 1015/875 max. tested in 1st for 15mph and 2nd for 25mph around 2400rpm. I figured it would be a good time to head off to the test only.

WRONG. My first mistake was going to a new test only place. My 2nd mistake was telling the guy to test in 1st and 2nd and that we got the nox way down.

I sat in the empty waiting room and listened to my jeep run the 15mph test at about 2400 rpm..shift into 2nd and rev to about 4500rpm followed by the dyno shutting down ( test abort) and then followed by the tech telling me that he could not run the test in 2nd cause the rpm are too high....no sh#t so was the mph. right then I knew I was screwed.

He said he had to run the test in 1st and 3rd.

I passed at the 15mph @2453rpm 645ppm nox
I failed at the 25mph @1585rpm 1448 nox
The tech explained to me that anyone can get good numbers during the asm test because you just hit print when the numbers are good...I know he is full of crap because My print out is for the entire run at 15/25 mph and was good for the whole test.

My ASM test shows the numbers as averages for the full run
hc ppm 19...nox ppm 230...co .03%...co2 15.3%...o2 .1%

I'd like to see the numbers for failed and passed nox with the rpm at both 15 and 25 mph for some 4.0 H.O. jeeps

this is a 5sd 410s and 33s.

Ah crap..how do I move this to the right section?

Socal 4.0 H.O. smog readings

After spending a few weeks screwing around on the smog dyno at work I finally got my NOX down..way down.. for the full ASM diag test on our smog dyno. nox down to 7ppm during our testing..averages for complete test 230ppm.. way below the 1015/875 max. tested in 1st for 15mph and 2nd for 25mph around 2400rpm. I figured it would be a good time to head off to the test only.

WRONG. My first mistake was going to a new test only place. My 2nd mistake was telling the guy to test in 1st and 2nd and that we got the nox way down.

I sat in the empty waiting room and listened to my jeep run the 15mph test at about 2400 rpm..shift into 2nd and rev to about 4500rpm followed by the dyno shutting down ( test abort) and then followed by the tech telling me that he could not run the test in 2nd cause the rpm are too high....no sh#t so was the mph. right then I knew I was screwed.

He said he had to run the test in 1st and 3rd.

I passed at the 15mph @2453rpm 645ppm nox
I failed at the 25mph @1585rpm 1448 nox
The tech explained to me that anyone can get good numbers during the asm test because you just hit print when the numbers are good...I know he is full of crap because My print out is for the entire run at 15/25 mph and was good for the whole test.

My ASM test shows the numbers as averages for the full run
hc ppm 19...nox ppm 230...co .03%...co2 15.3%...o2 .1%

I'd like to see the numbers for failed and passed nox with the rpm at both 15 and 25 mph for some 4.0 H.O. jeeps

this is a 5sd 410s and 33s

a mod has to move it, i'll put in a request for ya :cheers:

Re: Socal 4.0 H.O. smog readings

PM me.

Re: Socal 4.0 H.O. smog readings

1998 XJ 4.0/5 speed, 4.56, 35" MTR:

15mph@1655rpm, NO max - 522ppm, measured - 59ppm
25mph@1705rpm, NO max - 775ppm, measured - 28ppm


1996 XJ 4.0/Auto, 3.55, 225/75r15:

15mph@1615rpm, NO max - 527ppm, measured - 495ppm
25mph@1586rpm, NO max - 780ppm, measured - 98ppm

Tested in two different locations, but there it is.

moved it for ya then merged with your other duplicate thread

Anyone with a borla header have any readings? And I noticed my Borla has the o2 bung in the collector for the 4 5 6 cylinders. I need to know if a stock H.0. has the o2 reading all 6 cylinders.

I have a borla header and I have to change my cat for every test in order to pass or I fail on the NO readings everytime. HC and CO are excellent, it's just the NO that skyrockets and my engine runs cool.

15 mph 1649 rpm measured 26ppm NO

25 mph 1660 rpm measured 22ppm NO

1998 Sport, 32/11.50 tires, 4.10 gears

SanDiegoXJ said:

I have a borla header and I have to change my cat for every test in order to pass or I fail on the NO readings everytime. HC and CO are excellent, it's just the NO that skyrockets and my engine runs cool.

Click to expand...

Same here only last time the cat did nothing for me ( it was a bolt in cat from summit or jegs) and it was only in there for test day. What brand cat are you getting?

Original_MudButt said:

15 mph 1649 rpm measured 26ppm NO

25 mph 1660 rpm measured 22ppm NO

1998 Sport, 32/11.50 tires, 4.10 gears

Click to expand...

You have a borla?

Ok Heres the final numbers for this round.

15 mph, 1657 rpm, NO 0 ppm ZERO
25 mph 1582 rpm NO 3 ppm

Still like to see some numbers for 91-95 H.O.s because I't seems that this problem may be programing in the SBEC pcms and jeep changed to the JTEC pcm in 96


92 4.0 H.O. 5sp 33's 410's borla, spintec muff.

Tested yesterday 201,148 miles on odometer
93 4.0L HO auto

15mph 1662 RPM CO2 14.80, 02 0.08, HC 72, CO 0.11, NO 508
25MPH 1623 RMP CO2 14.90, 02 0.02, HC 39, CO 0.06, NO 289

hollywood32 said:

Tested yesterday 201,148 miles on odometer
93 4.0L HO auto

15mph 1662 RPM CO2 14.80, 02 0.08, HC 72, CO 0.11, NO 508
25MPH 1623 RMP CO2 14.90, 02 0.02, HC 39, CO 0.06, NO 289

Click to expand...

the lambda calculator says you where at 14.68 on the 15mph test (same as me) and 14.67 on the 25( I was 14.69)

JXPEEJ said:

After spending a few weeks screwing around on the smog dyno at work I finally got my NOX down..way down.. for the full ASM diag test on our smog dyno. nox down to 7ppm during our testing..averages for complete test 230ppm.. way below the 1015/875 max. tested in 1st for 15mph and 2nd for 25mph around 2400rpm. I figured it would be a good time to head off to the test only.

Click to expand...

When you are testing on your own dyne, are you testing in manual mode or pre-test mode? If you are in manual mode you need to change the load value for high and low speed tests. even then the true load is only a guess compared to what you will see during the actual ASM test. What brand of TAS do you have? Have you checked O2 amplitude and modulation with a lab scope? How about a cranking CO2 test?

badgeye said:

When you are testing on your own dyne, are you testing in manual mode or pre-test mode? If you are in manual mode you need to change the load value for high and low speed tests. even then the true load is only a guess compared to what you will see during the actual ASM test. What brand of TAS do you have? Have you checked O2 amplitude and modulation with a lab scope? How about a cranking CO2 test?

Click to expand...

The tests at our shop say ASM Diagnostic Test and runs the 15 for about 110 sec and the 25 for 110 sec. Is this manual mode? Or is that the one that you can drive anyspeed you want? Not sure the brand of the machine but it's exactlly like the one at the two different test onlys I went to. I did notice that if I run through the test and then repeat..the 15mph test sometimes would not apply load....and sometimes it would.
Those numbers I listed today were from the test only PASS. And funny thing is that this time the test would not let the run the 15mph in first and last time it did so I know the actual test changes it up a bit.

Did check the new O2 with a crappy scope and it moved up and down real high/low and pretty fast. Tell me more about this cranking CO2 test...

Just failed smog today....after going to the test only and idling on the dyno for about 25 mins while the smog guy did other stuff...like eat or something. My nox numbers were way up compared to the last test. 704 (711 max) 15mph and 502 (611 max) but failed on CO at 25 mph 1.02 (.65 max). Last test was zero and 3ppm on nox.


Wonder WTF? So I looked up this thread instead of looking in my smog file and see this time It got run in 1st and 2nd, 2362 and 2400 rpm. Funny last time I tried to get them to run in 1st and 2nd and the guy wouldn't......I had a bad feeling when the smog kid said " oh no...it's a stick?"

Now I'm trying to decide if I'm going to put on my test only cat or just tell him to run it in 2nd and 3rd ....for scientific purposes.