Confirmatory Test on Test Pipes and CEL

[Jacko3]

A few weeks ago I had written a small piece about Test pipes and how to avoid the CEL. Here is the link http://forums.g35club.org/zerothread/379452

Well, after the tune up on my car where the throttle body was cleaned, new airfilter, spark plugs, PCV valve, radiator fluid were replaced, etc., the ECU was reset to original parameters with the idle re-learn reset as well. This ultimately led to the CEL coming on a couple of times---3 times to be exact, after the ECU reset. As detailed in the link posted above, and as I have practiced, the ECU of the G-35 Coupe started re-learning its sequence once again, and after three incidences of CEL coming on, now the light is no longer coming on again. However, an easier way would be to add a second set of spark-plug anti-fouler to the first set of anti-foulers on the test pipes, which would have made the car run a little richer but with less CEL coming on.

Either the Alpha or Beta numbers in the ECU was reset by my technician (Stevethetech knows this stuff) back to 100% (I am not sure which it is--alpha or beta numbers). Normally, manufacturers allow for 10% below the set/perfect alpha or beta number or 10% above those numbers. The effect of this is that above the set alpha numbers, your car runs lean. Below the set alpha numbers, your car runs rich. The preset alpha or beta numbers are more for emmission purposes than they are for performance purposes.

Once the car re-learns how to make adjustments with the test pipes, it will automatically shift the alpha or better numbers towards being lean or at least 12% - 14% above the perfect/set alpha or beta numbers (state of the engine will determine how much above the numbers will be form the preset/alpha numbers). Your car may produce slightly more power but it will certainly fail most emission testings. Your car will also start using gas very efficiently----you may experience close to 28 - 30 MPG.

The alpha or beta limits of + 10% or - 10% are simply limits for emmissions purposes and has little to do with the safety of the engine or its power output. The VQ engine can tolerate a lot higher lean numbers, probably close to 30% above the preset/perfect alpha or beta limits, than the pre-set numbers in the ECU. However, this will come at the cost of repeated emission failures. However, under those conditions, one would be well advised to use a high quality and heat dissipating oil such as Mobil EP 1 Synthetic or Royal Purple to keep the engine in great shape. Premium gas or at least 93 rated gas is a must in order to avoid a potential for pinging under these conditions. So, it is a great advise to use Premium gas if you have test pipes.

And so, for those with superchargers and turbos, it is certainlya good advise to have a piggy back Engine Management Unit with the right tuning, if you intend to pass an emission test while increasing the power of your engine. Without saying, a new or additional fuel pump will be needed in other to counter any excessive lean the piggy back might create in order to reduce the NOX to acceptable emission limits, if you have a supercharger or a turbo system.

So, in essence, we have a car that can technically get 30 MPG on premium gas with adjustments to your alpha and beta numbers, with no problems. My car was running at 12% above the set/perfect alpha and beta numbers with no issues at all, prior to resetting the Idle learning volume and priot to resetting the alph and beta numbers in the ECU.

In fact, it is possible that with modifications, you can ask your technician at your dealership to deliberately move your Alpha and Beta numbers closer to 10% or even up to 13% without any issues, that is if it can be done, so long as you use premium gas all day long, and so long as you use a higher quality oil such as Mobil 1 EP Synthetic or Royal Purple---THERE CANNOT BE A COMPROMISE ON THE QUALITY OF THE GAS AND THE OIL UNDER THESE CONDITIONS. You will see some modest performance gains and increased gas mileage in your car, but at the risk of failing an emissions test. However, well before an emissions testing, you can always take the car back to your technician for the parameters to be reset back to their orignal settings.

I have an Mrevv, a JWT Popcharger and Z-tube, spacer, test pipes, Royal Purple in my engine, and all I got was just 12% above the set/preset alpha or beta limits, before the reset of these parameters, which meant that i would have failed any emmissions test, but then i had increased gas mileage and power gains.

This is very interesting stuff. Its amazing how our cars can be manipulated on the cheap. I am not sure why I need a piggy back system now since I have no turbo or supercharger or a Cobb tuning device, when i can do all these stuff literally for free as it stands, with my technician.