yeah so I have a 87 NA Supra, all I did with it was get it repiped to 2.5 inches past the catback, magnaflow muffler and resonator and I didnt pass wtf.
Didn't Pass Smog wtf
- Thread starter Rob_Supra87
- Start date
Here is the test, and there you see my connection, stock Cat, magnaflow resonator and Muffler with dual tips *not pictured*: so now I have to put the old one back on for the test...yay.
BTW did I need everything repiped at 2.5 for the power increase or is what I got good? I havent driven it at all yet *days off work* except for smog so I never got a chance to really try it out lol
BTW did I need everything repiped at 2.5 for the power increase or is what I got good? I havent driven it at all yet *days off work* except for smog so I never got a chance to really try it out lol
Did you take it in cold or hot? Taking it in at operating temp, and not shutting it off, will make a difference. If its at operating temp, you shut it off, and restart it, it's gonna run rich during the test.
The 2.5" pipe is fine, but you're gonna want to put a resonator in there. It's gonna drone unbelievably loud when cruising. Check the n/a section for exhaust help.
The 2.5" pipe is fine, but you're gonna want to put a resonator in there. It's gonna drone unbelievably loud when cruising. Check the n/a section for exhaust help.
Did it pass before you had the exhaust? If all the stuff in the system is new (specifically the cat) then changing the piping probably isn't going to do anything.
I have a resonator and it still has unbelievable drone I want to fix lol and it was at operating temp
Piping isn't going to change anything...
Tired cat (or cold cat) and/or in need of a tune up will cause a fail.
Tired cat (or cold cat) and/or in need of a tune up will cause a fail.
if your car is running at 5% CO, it has nothing to do with exhaust unless you have a exhaust leak near or in front of the o2 sensor. A cat (especially w/o air injection), is not able to reduce numbers like 5% CO.
also what was the reading of 02 and C02 during the test? and i am guessing running that rich the NOX numbers were low?
your car is running full rich, you have a fuel control problem.
also what was the reading of 02 and C02 during the test? and i am guessing running that rich the NOX numbers were low?
your car is running full rich, you have a fuel control problem.
tomorrow I will post a pic of the full test, I last got it smogged 2 years back when I first got it and it was pretty much perfect and clean so now its like wtf, any signs to look for for a leak?
Alright so here is the complete test broken down into 2 pics and the last pic is exactly 2 years ago when it did pass.
PrinceChip is correct. A stoichiometric feed gas will always contain less than 5% CO. Therefore, although you may need a new one to eventually pass, the catalyst is unrelated to the high CO. The engine is obviously not in fuel control, which it clearly was on the previous test. And that it passed two years ago is irrelevant...even more so considering you're comparing an Idle Test to an ASM.
Yep!
If you have HC & CO high then your timming is retarded or your fuel is to rich.
If you have a little room with NO then you could advance your timming a little to get it just right.
Emissions can be to rich because weak spark or plug wires, ECU have any codes like O2 even though it shows it pass on the paper it could be bad. other things like the EGR leaking to atmosphere putting more oxygen to the O2 will make the car think its lean and put more fuel in it etc..
bad knock sensors also retard your timming to create simular situations.
If you have HC & CO high then your timming is retarded or your fuel is to rich.
If you have a little room with NO then you could advance your timming a little to get it just right.
Emissions can be to rich because weak spark or plug wires, ECU have any codes like O2 even though it shows it pass on the paper it could be bad. other things like the EGR leaking to atmosphere putting more oxygen to the O2 will make the car think its lean and put more fuel in it etc..
bad knock sensors also retard your timming to create simular situations.
Your A/F's are 12.4:1 and 12.5:1 respectively. Massively rich and (as stated before) not in closed loop.
As always, start with the easy stuff. ECU codes and engine temp need to be verified. Could be as simple as a stuck thermostat keeping the engine cold.
As always, start with the easy stuff. ECU codes and engine temp need to be verified. Could be as simple as a stuck thermostat keeping the engine cold.
test and swap out the dead O2 sensor, new plugs, new premium gas, and rev the crap out of it for a minute or two (after operating temp) before putting it up on the wheels to get the cat hot.
Hell, a nice spirited run on the highway is best, and go at a time they're not busy so it goes right in.