Bracket Talk
MSD Grid O2 Replacement

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/5557048696

August 20, 2021, 10:28 AM
suprodn
MSD Grid O2 Replacement
Wanting to put a fresh set of O2 sensors in my Grid. What’s a good source for these replacements. Thanks
August 20, 2021, 10:57 AM
markemark
If they work properly now, why would you need to replace? Are you using leaded race gas, E85 or methanol?
August 20, 2021, 04:59 PM
suprodn
Mark
Running leaded race gas. I have been fighting inconsistent cruise RPM's on my throttle stop. There is also a dip in the RPM graph at times and not others when the stop comes on. The grid is showing a lean spike when the stop comes on. The grid also shows one bank to be leaner than the other. My O2"s are in my collectors. The carb is at ATM for a tune up. I just want new O2's when my carb comes back to have reliable data to try and solve these issues if they are still there. Is there a calibration process for the grid O2 system.
August 20, 2021, 05:07 PM
Rodney Pryor
I don’t think you get consistent o2 readings from the collectors on the stop. I may be wrong.
August 20, 2021, 06:03 PM
markemark
I’ve seen O2 graphs from sensors installed in collectors with little behind them and the readings were skewed at anything less than WOT. Maybe consider moving one O2 to an individual pipe and try using what you presently have to do a comparison.

I’m new to O2 sensors and have one in the collector on a Holley system now with methanol. There is 15” of pipe and short Dynatech muffler behind it that I believe provides excellent O2 readings coming off WOT and at idle.

I am looking at installing an O2 with Grid in the other side exhaust collector and send the analog signal to Holley.
August 20, 2021, 06:38 PM
bry-war
What type of throttle stop? If it's under the carb, I want to know how it can't be lean? Once the signal to the carb is diminished and the vacuum is pulling on the plate the fuel will go away...just thinking aloud
August 20, 2021, 07:13 PM
suprodn
It’s a inline linkage stop. Don’t have room in my scoop to raise the carb 3 inches
August 20, 2021, 07:45 PM
bry-war
Well the principle applies. When the throttle bores close and the signal goes away it will still have a lean condition while the crank speed is above your maintained stop rpm. Meaningless unless it won’t come off the stop clean. There are several threads at other sites about replacement cross reference O2 sensors that are not from the performance market