Installing an 02 sensor eliminator

[Ulvetanna]

(05-06-2016 08:23 AM)Gumby 1100 Wrote:  Ulvetanna,

Do you have evidence to support your view and that the use of the O2 Sensor Eliminator WITHOUT the use of a Power Commander or ECU Reflash might be dangerous?...Because, there are a lot of CB1100 owners running these Eliminator plugs, and ALL have noticed a marked improvement in drivability. Are the typical PCV charts for the CB really adding much fuel in the upper RPM ranges?

The evidence is that good practice when making changes to fueling is to always do a dyno run with air/fuel ratio before and after making changes to ensure the change has not adversely impacted performance or durability.

So the burden of proof lies on the entity promoting the product; without assurances that the elimination of sensor will not harm the engine - in the form of a proper dyno chart - there is no way to really know what's transpiring other than to take the word of the vendor.

Now I will also say it appears absurd that the O2 sensor does nothing but allow the bike to pass an emissions test; the standard line of thinking provides that the sensor will compensate for any type of slip-on or air filter change, obviating the need for a reflash or retune. This has been a widely-held understanding since the days that EFI become the rule for motorcycles, rather than the exception.

If the sensor performs as described in the earlier post, this would be untrue. But countless dyno runs done with many aftermarket slip-ons have shown adjustments made by the ECU to compensate for these mods. At least, this is what we have been given to understand all these years.

If the sensor did nothing above a high idle, no compensation would be possible due to altitude or for a leaner condition due to a high-flow air filter or less restrictive slip-on. So how would a bike owned by a guy in Denver CO (5,000' MSL), or, say Wrightwood CA (7000' MSL) possibly be able to run properly with a correct A/F ratio? Only two ways: either there is a temperature compensated altimeter built into the bike somewhere, or the O2 sensor adjusts for altitude throughout the entire RPM range.

Again, the burden of proof is with the vendor. Accept these things on faith at some risk.

I don't doubt that the bikes "feel" better; that would suggest to me that they are running perhaps lean, because the engine will make more power with an A/F ratio on the lean side. I've rejetted many a motorcycle with carburetors and this is always the case, but it's not good for the engine, especially for an air-cooled bike. So, yeah, it runs better and stronger, but what do the plugs look like? Anyone even ever pull them to see?