FAILED Emissions Test:(...UPDATE

[gmrulz4u]

I just thought I would update you guys on my Emissions Test situation...

 

I knew right after I had failed this past Friday that I chose the WRONG place to go!! They were rude, moronic, and were so much better than me that they didn't even look up at me while they were talking!!

 

So I called around today to find a place that actually CARED and LISTENED to what I was saying...and were at least POLITE in someway!

 

And I found a really awsome place with a great guy working there...he made me feel at ease after just talking to him over the phone!! He asked me what my failing "numbers" were and he said he shouldn't have a problem bringing them down to at least a pass...I thought "oh my God, this guy CARES!"

 

Anyways, I told him everything that had been done and what not...we also talked a little techy because I know my W-Bodys as well as any of you guys:)...I told him what I thought might be the problem etc...and he told me...he also contradicted a lot of what the other moron told me on Friday!

 

The only thing I kind of regret now is that I think I came across as being more in a position of just wanting to Pass, rather than really looking to solve some big problem. I guess I can see why he may have thought that.

 

He called me a few hours later and said he "got it to pass". Which tells me that he was really just doing what it took to Pass it for me and not really focusing in on major diagnostic stuff. Needless to say I was VERY happy!!!

 

He told me that he checked the entire engine for vacuum leaks and found none. He told me he cleaned the throttle body. Then he told me that he noticed that the O2 Sensor was not "switching at idle"(Rich to Lean to Rich etc.)...even though the O2 Sensor is brand-New...so he said he cleaned the electrical connector for it and was able to get working better. He said the car ran better with the O2 Sensor disconnected!!!

 

He said the engine is not mis-firing, which I thought it was!? He said pretty much everything else looked good except for that O2 thing. He thinks that the O2 circuit might be faulty and that the fault lies in the ECM itself. He told me that the ECM in my car is WELL known for it's poor soldering contacts etc.(which I already knew because of this site). He said he has had to replace TONS of the GM model 1227727 computers.

 

Anyways, my numbers aren't THAT much better...but at least I Passed!!

 

Here's my OLD numbers:

 

40 km/h

HC ppm = 69(Limit), 68(Mine) = PASS

CO% = 0.38(Limit), 0.04(Mine) = PASS

NO ppm = 777(Limit), 621(Mine) = PASS

 

Curb Idle

HC ppm = 200(Limit), 221(Mine) = FAIL

CO% = 1.0(Limit), 0.63(Mine) = PASS

 

And my NEW:

 

40 km/h

HC ppm = 69(Limit), 62(Mine) = PASS

CO% = 0.38(Limit), 0.04(Mine) = PASS

NO ppm = 777(Limit), 620(Mine) = PASS

 

Curb Idle

HC ppm = 200(Limit), 171(Mine) = PASS

CO% = 1.0(Limit), 0.16(Mine) = PASS

 

As you can plainly see, the 40 km/h results are almost the EXACT same as they were on Friday. But the Idle results are MUCH better.

 

The car itself acts pretty much the same as before it went in. I'm thinking that since the ECM is original, I might as well replace it anyway.

 

BUT, here's something I don't understand: The O2 Sensor is independent and not CONTROLLED by the ECM, so if a brand-new O2 is sticking "RICH" and not switching from Rich to Lean as quickly as it should, how can the ECM be to blame? The O2 is just a feedback sensor, correct? OR, do they share the same ground wiring or something? I'm just confused as to how a faulty ECM can cause an O2 Sensor to give false readings?

 

THANKS AGAIN!

[pbender]

BUT, here's something I don't understand: The O2 Sensor is independent and not CONTROLLED by the ECM, so if a brand-new O2 is sticking "RICH" and not switching from Rich to Lean as quickly as it should, how can the ECM be to blame? The O2 is just a feedback sensor, correct? OR, do they share the same ground wiring or something? I'm just confused as to how a faulty ECM can cause an O2 Sensor to give false readings?

 

Think about the O2 Sensor as being an input to the computer (just like your keyboard). If the data it sends back to the ECM is somehow corrupted (through bad wiring, a faulty contact, a poor solder connection,etc), the computer might actually react as though the car was running lean when it is actually running rich, or vice versa (perhaps not both).

 

My guess would be cleaning the connector was just enough to make the computer see both condictions. It's also possible that just moving the wire while cleaning it caused the same result.

 

Paul