PPEHeaders

iTrader: (4)

It probably runs a little more rich in open loop. During closed loop (idle, cruising and mild acceleration) the computer will adjust to 14.7 for proper fuel economy.

Can you email me your exact codes to sales@ppeengineering.com and I will take a look and respond.

PPEHeaders

iTrader: (4)

The computer does multiple tests to check the different emissions systems. Every time you disconnect the battery or reset a code the computer has to perform these tests again. The only way to pass the tests is to drive the car around like normal. It may take several days for them to pass.

Removing the catalytic converters will increase the exhaust smell and can cause carbon buildup on the tips/bumper.

lobuxracer

iTrader: (2)

There are four A/F devices in the exhaust stream. Two are wideband planar devices - these are your primary O2 sensors for A/F control. The other two are narrowband sensors only capable of monitoring the catalytic converter's efficiency decline over the years. One pair monitors cylinders 1, 3, 5, and 7; the other pair monitors cylinders 2, 4, 6, and 8.

The methodology Toyota uses to monitor the secondary sensors is far more complex than it used to be in the early days of closed loop feedback. They run a routine during normal operation where the program intentionally runs rich/lean to ensure all the sensors are working. If they fail to respond during this test cycle, a soft DTC is set. If it fails repeatedly, a hard DTC is set and the MIL illuminates. This is why it surely isn't some simple resistor or capacitor making the ECM think everything is OK. Honestly, I'm pretty amazed all the guys running headers don't have issues with MILs, it speaks a lot to the cleverness of what both PPE and Sikky have done to get past this.Doc - the sensors need to be a few things - first, they need to be installed correctly. That means with the right tools and using the factory torque requirements. Second, they need to have free air available. They ALL work only because one side of the sensor is exposed to ambient air. If the holes are clogged or blocked, or someone got oil or antiseize or some other pollutant in the air vents on the sensors, they will fail. Absolutely 100% of the time, FAIL. This also means if they get water splashed on them, you've got problems. Third, there are multiple codes for failure. If the heater circuit goes bad, it sets a code. If the A/F ratio does not meet the expected value in the table in the ECM, it sets a code. If there is an open or a short in the circuits (yes, there are multiple circuits because you have a heater and either one or two zirconium devices measuring what's going on) you set a code.

Troubleshooting starts with finding out exactly which code(s) is(are) set.

Claiming one or the other header "runs rich" is pretty unlikely unless there is a fatal flaw in where the primary wideband sensor is installed. I didn't see anything like that on either header design.

There are PLENTY of other differences impacting Caymandiver's runs vs. yours. You don't even run the same fuel - there are 200 different local fuel standards for gasoline in the US alone. So, it's just about impossible to draw the conclusions you are from the data we have. Too many other possibilities exist.

Finally, it is impossible for the secondary O2 to impact A/F ratios in any way, so it is impossible for the different SIM designs to be responsible for what you are observing. It's definitely something else.

scamsel

any update on your situation toothdoc?

ToothDoc

After replacing the A/F sensor with a brand new A/F sensor all was fine until last week. Got another CEL... but that one went away the next day. If it comes back, I'm going to change the extension. We'll see...