If you want a good test, get a wide band O2 sensor. I was in a class last month and the instructor gave us some good insight on EGR and air/fuel ratio. He is using a wide band O2 to try and prove/disprove HHO. He found that at idle or wide open throttle when the EGR is closed, the A/F is 14 to 16:1. When cruising at part throttle the A/F ratio is 18-19 to 1. He confirmed it through a friend in engineering... EGR does lower cylinder temps, but it does it because they are running such a high A/F ratio.

 

Ummm....that doesn't make sense. A leaner A/F mixture would result in HOTTER temps. I'd like to see this "confirming data" that proves EGR lowers cylinder temperatures and how exactly it was measured.

Also, the AFR is changed by the ECU with readings from sensors like the O2. Your readings are the difference between closed loop(cruising) and open loop(floored), not the difference between the EGR being open or closed.

 

Not something i would recommend...get a new egr valve...and press on its better for emissions and usually makes the truck run better with a tiny bit better MPG too... plus most of the time if the EGR is blocked or broken it will cause the engine to ping.... sometimes it helps the 3.0s very well but 22r's don't like it much those of you that have done it and have no issue are very lucky...

 

So many people have reported different results I don't see how you can say it's either good or bad. Mine has been removed for several thousand miles and I don't get any pinging. Last time I filled up I averaged almost 15mpg and that's with quite a bit of off-roading and towing a trailer in stop&go traffic. I don't see how I could have been getting better mileage than that with the EGR.

 

When the system is working properly it makes the engine more efficient. 15MPG is about what most of the 85-95 toyota trucks and runners got that nothin special.... believe me i've tried bookoo stuff with my truck to increase performace and EGR removal was one and my truck ran like garbage with it off... put it back out ran likea champ... like i said its not everyone.... mostly why our yotas don't have much affected performance by it is because its a simple vaccum valve on most other vehicles it is generaly electronicaly controled and or has a solinoid... alot of cars i've seen with pinging issues come in with a bad EGR valve.... and wrong gas.... EGR redirects unburned exhuast gases and hydrocarbons back into the conbustion chamber to reburn then thus ruducing emissions... by a lil....

 

15mpg in a 3.0 4Runner pulling a trailer and off-roading on 31x10.5's without the EGR tells me not having the EGR hooked up hasn't caused me any loss of mileage. If anything I gained mileage, but can't confirm it. Not to mention it runs like a dream. If it were such an important part I don't see how so many people can report positive results like this.

To add to it, I know my alignment is off and I know my speedo is reading about 3.3% too slow(confirmed with radar) so I highly doubt not having the EGR is killing my mileage.

 

Leaner mixture is higher temp, I guess that's the whole point. The reaction with the EGR causes lower cyl temp at the leaner ratio. I'm new to fuel injection on the gas side, been a diesel mechanic for around 15 years and EGR destroyed those engines. The test vehicle this guy is using is a newer model Ford 4-banger. I think that has a lot to do with the results. They are intentionally lowering AFR at cruise and using EGR to lower the temp.

Being new to the gas side of life, I was told wide band O2 compared to normal O2 sensor is like telling if it's daytime by using the sun/moon or an atomic watch. Does this sound right ?

 

Yes, narrowband is basically garbage compared to wideband O2 readings.

So you're saying that he was activating the EGR at cruise while it was ~18:1 and the cylinder temperatures lowered? How was he measuring the cylinder temperatures? Coolant? Oil? Exhaust?

 

He was watching the wide band readings while monitoring engine PIDs with a laptop. What he found was an accidental observation. While cruising at steady speed, EGR flow goes up and AFR goes up with it. The engine power requirement is lower when the desired speed is attained and cruising, so the ECU increases the EGR flow and brings the AFR up to 19:1 or a bit higher. EGT (exhaust gas temp), stayed consistent. He said this confused him, so he called the engineering dept and confirmed that that was supposed to happen. That's how the American made cars have been able to gain some ground on the foreign makes in mpg.

I'm still waiting to get another class up there so I can pick up some more on this. I've talked with some other gas burner guys and they have the same thoughts... remove EGR and pick up power, but you will lose mpg on the newer EFI. The rumor is that they found the EGR trick by reverse engineering some Asian motors.

 

What vehicle/motor was this done on?

 

That's what I'm wondering too. Running AFRs of 19 and 20:1 aren't exactly easy to achieve with the average 9:1 gasoline engine.

Yeah, that about sums it up. Narrowband sensors have a very small range of accuracy right around lambda(λ) = 1 or AFR ~14.7:1 for gas. Even then they only report λ by flip-flopping between rich and lean. Wideband sensors have a known voltage output curve that corresponds to a broader, more useful range of λ readings.

 

abecedarian told me that having a wideband O2 sensor doesn't tell you anything about what the ecu is doing. the stock o2 tells you whether the exhaust is rich or lean, which a wideband sensor would do, but the ecu doesn't care how much rich or lean just cares if it's rich or lean. so when the o2 says rich the ecu makes the mixture lean until the o2 says its too lean then it make the mixture rich until the o2 says the mixture is too rich. and it moves back and forth around that point. not the most efficient way to do it but the best that could be done with the early 80's tech.

 

On top of that, the narrowband sensor isn't usually used during idle, open loop, or WOT.

 

I'm not sure of the year, but I think it's an 06 Ford Focus. I'm hoping to get into a class later this month to get more details and find out if he was able to prove/disprove the whole HHO thing. Classes are pretty boring, but you learn alot during breaks.

 

theyve come a long way with engines since the 80s... our engines are a totally different animal than a 06 focus