I have a trans am 91 with lb9 205 hp with 5 speed and 3.08 gear. The car is stock except i removed the cat. I have no code and my timing is at 10. Is it possible that my 02 sensor doesnt work properly if i dont have any code!!!

Finally, running without cat, can it increase fuel consumption or bad mixture o2/fuel?

thanks


[This message has been edited by stallone (edited February 03, 2001).]

 

Bump your timing back down, your knock counts are probably high. Have you switched to a lower temp thermostat? Check your BLM/INT to see what the ECM is seeing.

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-Jason M. 1991 Camaro Z28

 

Could be that the o2 is old and needs to be replaced. Also, have you had a recent tune-up?

 

Can you explain me this sentence: "Check your BLM/INT to see what the ECM is seeing."

I dont understand blm/int and what does mean ecm?

thanks

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trans-am 91 3.08 posi 5.0 lb9 5 speed stock

 

The BLM/INT is your Block Learn Multiplier and your Integrator.....you will need a scan tool or a diagnostic program such as Diacom in order to see these values. They range from 0 - 255 with a desired value around 128. Viewing or recording these values during normal driving will let you know if the ECM is adding or subtracting fuel, and how much.

 

is it possible to adjust ECM?

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trans-am 91 3.08 posi 5.0 lb9 5 speed stock

 

Can you guys add more to this subject? I have had the same condition for 6 years now, ever since I gutted my cat. I have a scanner, what am I looking for in it? What should be the BLM values for idle speed. The car really stinks a lot at idle and makes my eyes water. This has always happened, even when it was bone stock.
Thanks, Rick

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'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, intake pieces and 2100 RPM TQ

13.40@102.55 MPH
1.90 Sec ------- Best 60FT
104.23 MPH -- Best Trap Speed

AIM HIGH!

 

BLM/INT values of 128/128 is a "perfect" mixture via the tables and associated sensor input readings while in closed loop. When you are in open loops or in WOT mode, you rely soley on tables and various sensor input readings and will ALWAYS have a value of 128/128...which at this point is meaningless.

All these "tricks" to modify sensor input readings to fool the ecm is not the way to do it. Changing the eprom is the proper way and yields the BEST results. Faking the system may improve the running of your engine under certain circumstances, while causing problems in other areas.

The ecm and its associated sensors are a "system" that is designed to work in harmony. To properly maintain this harmony, you need to attack the problem at its source; the eprom.

 

Glenn, what I'm trying to find out is if the gutted cat caused all the rich, stinking condition??