EDIT: fuel pressure, regulated, and unregulated are in spec. 34psi regulated, unregulated 44psi


Hows it going HT. i really need some help here!! I have a 94 civic DX- stock d15b7 w/166,xxx mi. Only mod is an AEM cai. I've failed California smog 3 TIMES, this time around for high NOx during my low speed ASM test. 2 years ago, i failed for excessive NOx (15mph, max 732ppm. measurement= 1000ppm). I was instructed to replace the Cat by the Star Certified, test only Smog Tech. I then replaced the stock Cat with a Magnaflow California approved, direct bolt on converter, and passed the emissions test with flying colors- NOx was almost non existent. Fast foreword to 2 years later, 7/2014, I take my civic for its bi-annual smog inspection, and expect to pass. I ended up failing AGAIN for excessive NOx on my low speed test. This time, my NOx was at 1400PPM during low speed vs. the maximum allowance of 732ppm. I had not performed ANY modifications whatsoever with my engine, or any smog related components. BUT I DID notice that my car stumbles a lot during idle(possibly lean misfire) on cold starts, and after warmup, it still stumbles a little. when i drive/load put on it, i don't notice a miss.

7/23/14: 15mph: CO2: 15.2, O2: 0.0, HC: 9ppm, CO: 0.03, NOx: 1465ppm
25mph: CO2: 15.2, O2: 0.0, HC: 5ppm, CO: 0.06, NOx: 233ppm

This time around, i figured i was running really lean, causing high combustion temps, which leads to high NOx. So i: checked thoroughly for vacuum leaks- none found, retarded ignition timing from 16 deg to 12 deg (this guy doesn't check timing for some reason), checked and replaced O2 sensor w/Denso sensor, checked and replaced ext sending unit, checked Map,TPS, checked function of IAC, cleaned and reset idle speed, fully seated my FITV, performed Carbon Treatment and replaced spark plugs with NGK factory replacements, performed Valve lash Adjustment, replaced ALL fuel injectors, and replaced fuel filter. So after ALL of that **** was performed, i filled my fuel tank with 91octane, and i took it in to get tested, and FAILED AGAIN for excessive NOx. this time, my measurements were:

9/22/14: 15mph: CO2: 14.9, O2: 0.0, HC: 10ppm, CO: 0.03, NOx: 1318ppm
25mph: CO2: 14.9, O2: 0.0, HC: 7ppm , CO: 0.03, NOx: 314ppm

The same Star Certified Smog tech tells me to use some Octane booster, some Cata-clean, and to come back in for a retest. Instead of doing that, i just went to purchase another CA approved, direct fit Cat from Walker Exhaust. Having my timing still set at 12BTDC (as retarded as i could set it) with the cat installed and warmed to operating temp, i took it in to get smogged AGAIN, and failed for ******* excessive NOx, WORSE THEN LAST TIME.

10/13/14: 15mph: CO2: 14.8, O2: 0.4, HC: 6ppm, CO: 0.03, NOx: 1756ppm
25mph: CO2: 15.0, O2: 0.2, HC: 5ppm, CO: 0.03, NOx: 792ppm

On top of all of this, the Star Certified, "test only" smog tech told me that my ignition timing was set at 28BTDC this time. He shows me with his timing light, and he's looking at the TDC mark on the crank pulley, aligning with the indexes on the timing belt cover. I tell him thats the wrong mark, and he tells me that its the right mark, completely not noticing the 3 timing marks also located on the crank pulley. And thats where I'm at right now. Can someone with some experience PLEASE HELP ME?!?!?!? These high combustion temps are killing me! NOTE: no EGR is used with these engines. Please, i hope i didn't write all of this for nothing lol

 

Sorry. Didn't read long post. The engine is running lean. Did you replace the fuel filter and measure the fuel pressure? Did you adjust the ignition timing correctly. It too is out of spec.

 

Yes, i replaced the fuel filter. I did not measure fuel pressure. The fuel pump (airtex) is about 3-4 yrs old. I set ignition timing using Alldata procedure, and set it to 12 deg BTDC, since the tech wasn't checking my timing the first 2 times, and Retarded timing= lower combustion temps.

 

Why do the tech notes state 28 degrees BTDC?

 

From original post:
On top of all of this, the Star Certified, "test only" smog tech told me that my ignition timing was set at 28BTDC this time. He shows me with his timing light, and he's looking at the TDC mark on the crank pulley, aligning with the indexes on the timing belt cover. I tell him thats the wrong mark, and he tells me that its the right mark, completely not noticing the 3 timing marks also located on the crank pulley.

 

Haha...

Measure the fuel pressure and test the FPR.

No CEL codes?

 

will do. should i check it at the fitting on top of the banjo, on the fuel filter? and how would i check the FPR? just unplug the vacuum hose on the FPR while I'm checking initial FP while its running? thanks in advance for the help!

 

yep

 

awesome! thanks for the info! ill get ahold of a fuel pressure gauge, and let you know how it goes.

 

had a chance to check fuel pressure. regulated: 34psi, Unregulated: 44psi. anyone else with any tips?

 

https://honda-tech.com/honda-civic-d...-help-3206424/

"Update: Passed emissions! I put in a bottle of Guaranteed to Pass gas formula, put a p75 ecu in and drove for a good 45min on the freeway and straight to the Emissions station. Passed my test with flying colors! Thanks everyone that tried helping me, much appreciated. "

 

You seem to be posting the wrong thread.

 

I was trying to reference the guaranteed pass formula, And while its not the same vehicle someone else who had luck with the product.

 

You don't need that crap to pass emissions. You got past the test but your engine is still running like crap.

OP try having your injectors serviced. They tend to be clogged up and have a **** poor spray pattern.

Read your spark plugs. See if some cylinders are running rich and others lean. Maybe pull off your intake manifold and clean it out. Do a valve adjustment. You need a balance between cylinders for proper fuel correction.

 

/\ but if you need to get to work in the meantime. Its better than driving illegally...

 

Guaranteed to Pass is almost pure alcohol. It does work, but only under certain conditions. The P75 alone would've made you pass because you'd run rich with it.