This is my major concern with deleting the EGR. Putting a resistor on the EGR temp. sensor could cause a lean condition, It may not be enough to be concerned about but that is what I'm not sure of.....
The purpose of the first O2 sensor is to correct fueling with short and long term fuel trims. Any small changes will just be reflected by a percentage in the long term fuel trim.
There is a limit to how much the ECU can compensate for lean condition via long term trim. It is probably enough, but I don't know for sure. When you compensate by adding fuel, you are getting worse fuel economy. You get better MPG by adding combustion gas via the EGR. That is one of the two reasons you have an EGR, the other being reduction of NOx.
Long term effects on the motor is my main concern. That is why I had planned on doing the delete. I had always thought the EGR was in a way "bad" for the longevity of any motor... Now I'm not sure. I spoke with a Toyota mechanic today that I have known for years.... His feeling is that it really was not worth removing........ It's Coke vs. Pepsi I guess
I think it is, but yes coke vs pepsi, ford vs chevrolet, you name it people have reasons to keep it or get rid of it. But there is no reason in my opinion to have hot exhaust gases running up by the main wiring harness and back into the engine. Except for emissions.
At high speed cruising conditions, like 65-70 MPH on the highway, you don't need more power, but you could sure use better gas mileage. The EGR allows a leaner mixture and lowers pumping losses under highway cruising conditions. If you have an EGR, it is better to keep it operating properly.
found out some good info today for OBD 1 folks...... i bought a new engine harmess(94')(82121-60341) It has the OEM resistor(82824-35020) already installed. I believe, because (93-94.5) have same harness and same ECM. Since some 93' have no EGR temp sensor but have same ECM as 94' this tells be the 94' is just as easy to convert at least electronically, to NON temp sensor and NON EGR...
You can unplug your O2's and you wont have to worry about running lean with the EGR disabled. It runs rich in the default mode when the O2 are unplugged.
As for long term affects of EGR on motor, my motor has had its EGR hooked up for about 3/4 of its life.
Its at 417,000 mi and still going strong. I dont have any idea if an EGR harms the motor but I do now that it
make the intake plenum dirty.
I was worried at first about running lean when I messed with removing EGR and O2's but didn't have money to buy a air fuel mixture gauge.
If you worry about lean conditions, you could stick a air fuel mixture gauge on you exhaust. Might even go in the hole for the PAIR system is on the manifold.
Have no idea what STOICH means.
Catalysts are strictly for smog reduction (HC, CO and NOx), so you would not find them on non-smog controlled engines. If you have them, you may as well keep them because they work and there is no down side as long as they don't get clogged.
