b20vtech

smog guy says that my car is running lean.... what could be the cost of a stock civic running lean?? what should the fuel pressure be at on a stock 94 civic cx 1.5Liter?? what should i change?? cars been sitting for couple of months due to a rod snap, made a big hole on the block... so i put a new use engine in it...should i change the cat and o2 sensor?? what can i do to find out that my car is running lean??

john666

im not a pro smog guy or anything but do you have your smog printout ? if so maybe put the info up and im sure someone can help u further

ek_chris

i assume you failed on NOx. It isn't necessarily running lean. It could be carbon build up, weak cooling system, etc. Assuming those are in check, I would start with a tune-up (if you havent done one in awhile) and check all your sensor parameters and make sure they are up to spec.

FPR should be at 36 with the vacuum hose on (at idle) and about 45psi with the hose off (WOT).

thesmogman

When you blow a motor alot of oil/coolant usually goes thru the exhaust. Which in turn will take out the cat, or at least degrade it's effectiveness.

O2 sensor can be bad for the same reasons.

What was your HC numbers? if they are in the single digits O2 sensor would be my best guess. Unless you have a vacuum leak.

Also what are the O2 readings from the report anything above 0.5 for both parts of the test points to the cat, could be part O2 sensor too. You would like to see 0.0 for the 25 and at least 0.3 for the 15.

EJProject

Yeah, I'd go with a cat, 02 sensor or something screwy with the vacuum. I don't remember if CX's had EGR or not, but that maybe something to look to as well.
Check your plugs too.

slowcivic2k

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ek_chris &raquo;</TD></TR><TR><TD CLASS="quote">i assume you failed on NOx. It isn't necessarily running lean. It could be carbon build up, weak cooling system, etc. Assuming those are in check, I would start with a tune-up (if you havent done one in awhile) and check all your sensor parameters and make sure they are up to spec.

FPR should be at 36 with the vacuum hose on (at idle) and about 45psi with the hose off (WOT).</TD></TR></TABLE>

IF you fail NOX you are running lean, the only time that NOX forms is with high exhaust/chamber temps (1200-1600degrees) If your EGR is inoperative (eventually they clog with carbon) this will make you fail, EGR is there to reduce NOX by cooling it in the intake and thus reducing combustion temps by way if introducing an inert gas.

A typical reading goes something like this:
HC 10-25ppm (ideally 0)
NOX 50ppm or less
O2 0.5% or less
CO2 12-20% ideal
CO 0.5% or less

HC indicates unburned fuel, as im sure you all know.

NOX indicates high combustion temperatures, which is combated with EGR

O2 is your lean indicator, if your NOX is high, odds are O2 is nonexistent, making a lean condition the cause of high NOX.

CO2 is your combustion efficiency, when there is enough oxygen present for combustion, it forms the more stable CO2.

CO is the rich indicator. If this is high, odds are HC is as well, because there is not enough O2 present to form CO2, so it forms CO instead.

A bad thermostat will fail your for NOX because coolant temperature play a role in preventing NOX, as a thermostat controls the engines minimum operating temperature. Ideally run the emissions test with water in the radiator and ethanol blended fuel if you are really pushing the limits of pass or fail.

Bring your test results in and ill be able to help pinpoint your problem.

b20vtech

sorry i dont have a print out sheet, cause the smog tech guy dint give me one.... i droved it really hot before i smogged it because i have herd that alot of people do that to pass their smog... eventually it dint pass.... so i ask smog tech guy and he dint really want to tell me whats the real problem... he just said that maybe it's running lean and he could fix it for $250... so i said i'll find out the problem myself..... me and my friends have pass smog with this CX motor plenty of time... so im almost 100% sure it's not the motor.... i'll try to see if i can get a print out sheet next time i bring it to smog...

EvilPhu

Did you see the reading??? don't trust the smog tech if he's not giving u a print out, go somewhere else. Go to a smog station that give a free RETEST, test it first and get a print out reading.

slowcivic2k

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b20vtech &raquo;</TD></TR><TR><TD CLASS="quote">sorry i dont have a print out sheet, cause the smog tech guy dint give me one.... i droved it really hot before i smogged it because i have herd that alot of people do that to pass their smog... eventually it dint pass.... so i ask smog tech guy and he dint really want to tell me whats the real problem... he just said that maybe it's running lean and he could fix it for $250... so i said i'll find out the problem myself..... me and my friends have pass smog with this CX motor plenty of time... so im almost 100% sure it's not the motor.... i'll try to see if i can get a print out sheet next time i bring it to smog... </TD></TR></TABLE>

Don't get your car smogged by a chimp, I would take it to a dealer and get it smogged if you have one in your area. I would not trust a chimp that isn't gonna give you your results, and then offers a repair....