Originally Posted by kveldulv

Hey guys new here, i have been searching all over the net for the past 3 days on some help with my problem and I am to the point of either shooting the truck with as many rifles as i can get my hands on until it looks like swiss cheese or beating my head against a wall.

I have spent much time and effort in building this truck up from a hardly running heap into the truck it is now until 3 days ago when i changed out the manifold for headers.

So i installed new headers, drop in new E3 spark plugs, installed new o2 sensor in the headers bung, and kept my K&N filter. Also another note the cat was removed prior to the headers and it ran just fine so it is going from the y-pipe straight off onto a 2 stage flow master muffler.

Now when i installed the headers i found out that the smog pump/secondary air injection system had to go, no where to plug it in and relatively useless i know, since in the state i live in we do not have emission checks im clear to leave it off.

The problem is that the system seems to hate the headers. Scratching my head it looks to be that the O2 sensor is now reading a higher voltage because the SAI is not longer forcing O2 down the exhaust up stream from the only O2 sensor this truck has (its an OBD-1). So the ECU i think is thinking the engine is running super rich and is leaning it out. Now it sounds to run fine at idle which is kind of odd but when you give it gas under load (neutral it revs just fine) it just trips over itself lack of power, backfires and generally runs like someone pooped in my tank.

I have heard everything from the O2 sensor isnt going to get up to operating temps (its a single wire) because of the headers and i need to replace it with a 3 wire system (check the 3-wire sensor and plug is on the way to wire that in ASAP).

The main issue i worry about is if the ECU is adding a value to the O2 sensors value by default because of the SAI was suppose to be there. If this is the case then even with the 3 wire O2 the system is going to have just as much issues and i need to some how reduce the voltage off the o2 sensor to trick the ECU in order to prevent over leaning the engine.

Now first off i removed the K&N the other day and put in a normal ol restrictive paper filter just in hopes of getting some of the problems fixed, not much of a difference there so back to ground zero.

Other options i found were to get a custom eprom, etc however with the cost of an Eprom i could build some kind of potentiometer controlled voltage reducer to control the volts going to the ECU for about 40.00 rather than 300.00 for a new eprom.

Any insight on this issue would greatly help out guys I am at my wits end.