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Smog Help

2K views 26 replies 4 participants last post by  female four 
#1 ·
I am having a problem with smog. I have a P28 computer and it is dumping fuel into my b20. The car is a 95 gsr. It is running rich and my emissions are high. I do not know if I can change my computer or reprogram the one I have. Is there any one that can help me? I am only working with $200 and I just want to get my car on the road so I can work and provide for my family.
 
#2 ·
Can you provide a bit more information on your build?

Is it a full B20 swap into your GS-R shell? Do you have a B20VTEC?

Is the P28 chipped/tuned?

Have you considered a bad/clogged cat? You have an upgraded fuel rail, which in most cases makes you run a tad rich if you're running anything under 300whp or so. Is the fuel pump or Regulator stock?
 
#3 ·
Yes it is a full b20 non vtec. It has cams and a few other internals. I was told that the this car was tuned very well; I do not know about a chip. The cat is brand new and it has a DC header. The smog technitian told me it was running rich; the numbers are high. I only get 16 miles per gallon on the highway.
 
#4 ·
Do you know what your Air/Fuel ratios were?

A quick fix to lean it out would be to purchase an adjustable fuel pressure regulator and gauge, and just crank down the fuel pressure until you get proper Air/Fuel ratios (as seen on a wideband A/F setup you would need to purchase).

The real way would be to get retuned at the dyno. If you are tuned, and you have a P28, you would most likely have a re-programmed chip in the ECU tuned with one of the OBD1 ECU tuning softwares (Crome, Uberdata, Neptune etc.)

Did you fail for any other reasons other than running too rich, and the side effects that running rich causes?
 
#5 ·
I do not know how to determine the air/fuel ratios. Would that be on the smog paperwork? Do you know where I could buy a fuel pressure regulator and gauge?

Yes I also failed beacause the check engine light does not come on and also my timming is off at the rpm's they were testing. I am guessing that has something with the engine being a b20. He did not say anything about the b20 being in the car and I live in california.
 
#6 ·
Hopefully somebody else chimes in about Smog testing rules. I live in a "do whatever you want to your car after you get your safety" world.

Air/Fuel ratios can be shown to you on a gauge that gets its information from a wideband O2 sensor you purchase (you want a wideband sensor with a digital gauge). B&M makes a nice FPR, and usually it comes with a gauge when you purchase it on eBay. However, the Air/Fuel equipment will be expensive (probably in the $200 area), and the FPR/gauge will be over $100.

But they are all required equipment when you start modifying the motor like you already have (the FPR less so, but it helps in tuning...cheap builds use it as the only tuning method, but the most of the tuning needs to be done at the dyno using your P28).

Timing can be set with a timing light by a mechanic. But, all of your problems should go away if you go get a proper tune from an OBD1 Chip tuner.

Your $200 budget won't cut it in the long run. Think closer to $600ish for all parts, tuning, and dyno time.

The fastest fix MIGHT be to increase fuel pressure with the FPR, but you'll still have the CEL problems, because it's probably related to your P28 tune.
 
#7 ·
why would you be using a p28? I assume the car came that way....

being that there's a p28 in a gsr, it's probably chipped. a p28 would not make your setup run rich unless you have big cams with a lopey idle and even at that, it would only run rich at idle. That's further evidence that the ecu is chipped. Also, I assume the previous owner told you it was tuned.

Chances are you have a chipped ecu and it's not tuned at it's best.

You have two options.
1. take it to someone who can tune it for you. cost ~$300
2. buy an obdI p75
 
#12 ·
Yes it is. You need to have a tuner take your chip out and reprogram it like you would a CD-RW so your various Fuel/Ignition maps can be properly dialed in. You'll get max power, max reliability, and max driveability. All while passing smog....if you can get around the engine swap lol. It's an OBD1 shell, so having an OBD1 computer hopefully will be okay, even though it's not the stock P72 that comes with the GS-Rs.
 
#17 ·
I just want to note that a stock p75 won't be ideal for max performance and it may make you run lean in open loop function which basically means full throttle and high rpm

Once you get your emissions straight, I suggest you get tuned using a FPR, AFC, or ecu tuning
 
#18 ·
Agreed:D

If you find a tuner in your area who knows the smog rules, he may be able to do your performance tune, and still stay within the constraints of the smog rules. Search around for some Honda tuners, and get in touch with them. Otherwise you'll have to swallow the cost of getting through smog, and having a pretty crappy performance/reliability tune, and then getting tuned for real later.

Getting a good A/F gauge and sensor will at least let you monitor your A/Fs as you drive so you don't blow the motor.
 
#20 ·
Hahaha. I'm guessing you aren't allowed to have the B20 in there? And yea, you're running rich at low RPM is due to your Crower cams. I guarantee you're running way lean up top and at WOT...unless you're on a really conservative, but crappy tune.
 
#21 ·
I was guessing my cel is disconected. It doesnt come on when the car is started. I thought my cell would be more complicated, because of the moter swap. I know one tuner who might be able to help and I would have to go to another person for the smog. Im just worried I will pump money into this car and still not pass.
 
#22 ·
Well, have a chat with the tuner, and if need be, make sure you can at least pass smog. That might mean you just have to baby the car on the roads, and drive like a granny.

But you know in the long run, you'll need the Gauges/sensors, and FPR.

Hopefully the tuner can make your P28 make your car seem stock so you don't have to get a stock ECU to trick smog. Try searching the net for "tips to pass smog" and topics like that. There are thousands of threads like that around, probably on this site as well.
 
#24 ·
It's just whatever the tuner or dyno operator charges.

My dyno guy charges $100 for the setup and 3 runs, and $100/hr after that.

My tuner charges like $50 per tuning session. You don't need a dyno to tune if you have the AFR gauges...but it is easier. It's called a street tune, and obviously you can't measure your horsepower.

A stock GS-R map is already burned onto the chip obviously if the ECU is stock.

The tuner can do multiple chip burnings per session for your performance tunes. The chip in your ECU is like a CD-RW...just keep burning it with new info based on your dyno run results.
 
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