Hey guys got a smog issue. I have replaced dist,plugs,plug wires,new fuel pump,new air flow valve,new 02 sensor,new cat,new coil,new muffler,but now recently developed a small leak in header gasket could that cause me to fail smog test(in ca)5.7 tpi iroc z-28 Many Thanks for any help

 

I live in reno nevada and both of my header gaskets are leaking bad and I still passed smog... i dont know if that will help you but....

 

a small leak no, a huge leak can actually draw oxygen into the exhaust causing abnormal readings which could cause a fail. doubtful though

 

What numbers are you failing? CO, NOx.....? If you can post the emission test results that would be helpful.

 

Here are my numbers CO2= 12.9 & 12.00 failed, 02=3.12 3.40 FAILED , hc =129,103 FAILED, NO'S were the big fail at 1802 & 1682
I have less than a year old top of the line magnaflow cat only things not replaced as yet is EGR all other components been replaced. It is running ok no foul smells. I did notice yesterday one of my cooling fans went out but car is not overheating, and it's running good no stalls,fumbles,idles ok. I have noticed my gas mileage has been poor lately. Any input is greatly welcomed Thanks guys

 

What are the limits?

 

see next post

 

Here are my numbers, first num low mph,sec higher mph: Actually the c02's = 12.09&12.00 and 02= 3.12 & 3.40 are just meas but he said they should be higher.
the limits are HC's max = 78 & 83 failed at 129 & 103, Co's max 0.71 & 0.40 passed these .09 & .05. NO's max 537 & 494 failed at 1802 & 1682 any suggestions I am desperate have replaced everything including cat and o2 sensor which was badly fouled. (Could I have burned up my cat) it is less than year old a magna flow.Have not replaced EGR yet and still have header leak,problem is running out of money. On disability fixed income sucks. Thank you for any help.

 

Are you burning oil? How is your ignition, is there any misfiring? How's your timing set? No vacuum leaks?

 

nope not burning oil, it was running rich before 02 sensor was changed. Car is running good except for irritating sound of header leak. Not misfiring, no stumble, Timing has not been checked but the smog guy didn't say anything about it being wrong. Does the header leak count as vacuum leak? It does have some kind of OTC performance chip. Other than that I don't think there is any. Vincent is going to help me fix the gasket leak I can get him to check it over maybe

 

is the air injection system still in place on your car? if this has been removed it would seriously increase nitrous oxide emissions. my 87 doesn't even need to pass emissions in Massachusetts.

 

How would a missing AIR system increase NOx?

 

nope totally all emissions equipment is there

 

because the added air helps to break down NOx in the catalytic converter into nitrogen and oxygen, thereby reducing smog.

 

Air is added to provide oxygen for catalysis of CO and HC emissions. Reduction of NOx actually decreases in excess oxygen.

 

I had similar issues here in Nevada, I went to the DMV Smog Lab and they wouldn't pass me either (trying to get classic plates). Went home and replaced the Hypertech chip with the original and changed oil. Not sure if yours has a chip, but I would strongly recommend changing the oil right before you go in. Just my .02.

 

It does have a chip did yours pass after you replaced it with stock chip?????

 

I don't remember the exact readings, but I do remember NOX was really high. The nice thing about the Emissions Lab, they didn't charge me for not passing. So I went home, pulled the prom out and reinstalled the oem prom and went back and passed with flying colors.

 

Cheap aftermarket chips usually increase the advance, which increases NOx.

 

Dang the PO put the thing in I just found the box a few days ago in that back side storage compartment man I am going to see if the original chip is there right now !!! If it isn't anyone know how I can get an original 87 5.7 chip ????

 

holy moly I found it !! Boy I hope this works

 

GOSH ON-GOING SMOG SAGA
ok I replaced the hyper tech chip with original chip passed everything but NO's are still high so here is my question. Can my less than one year old 300.00 magna flow cat be bad? The very first test my 02 sensor was bad and my no's were very low like 0162 now after everything's been replaced except new cat they are 1435. I hate to face my cat got ruined somehow

 

Couple of questions:

1. Did the car ever pass with the headers installed? I'm thinking it must have since it would have been tested before you bought it. When I installed my SLP tri-y's years ago, I had trouble with the exhaust retaining heat.

2. The EGR could be working but the exhaust passages could be plugged.

3. If the "new" cat is bad, something killed it. Was the engine ever running rich after it was installed?

4. Is your Magnaflow CARB/CA certified? Some will say it doesn't matter, but I'm beginning to think it does. Personally, I'm still on the fence on this.

My '87 hasn't passed since 2005. ERG is operational, passages are clear, new O2 sensor, new Catco cat, scan tool shows mixture in spec. It still won't pass. I'm running SLP Tri-Y headers; engine is otherwise stock. Next step is a CARB certified Magnaflow. They're priced around $180 on ebay (free shipping).

 

the smog record's show it has passed all the way back to 2005 this is first year it hasn't past and yes I had ca smog legal headers put on before it was smoged. It was running rich before I changed the 02 sensor and took out the perf chip,so I am guessing that it what killed my converter I guess. I will have to check my papers to see if it CARB/ca certified I thought it was.

 

I drove my '87 Acura Legend around for 11 months with an intermittent miss (bad plug) and it killed the cat.

If it's a CARB certified cat, it should be stamped with a D-xxxx number and easily seen with it installed.