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I just put a set of headers on my 89 Camaro which has a TBI 305 motor. Headers are the ONLY mod to the motor. Everything was fine beforehand. I took care of a leak and replaced the gasket on the passenger side, but the problem persists. At idle, the motor runs extremely rich and the exhaust pops randomly but frequent (not very loud but annoying). My guess is that unburned fuel is being ignited by the cat. My O2 sensor is new, but that doesn't mean it's not bad, it's also located about a foot further downstream than stock at the end of the driver's side collector. I'm half tempted to try the O2 sensor from my V6 Camaro because it operates in the Y-pipe in front of the cat (about 3 more feet downstream). Any insight???

EDIT: Sitting here, I just thought of something I should check. I had to lengthen the harness end of the O2 connector so that it could reach the new location. The new location is on the back side of the collector where the original was on the front side and a little closer to the head. Being rotated around like that, I needed wire to cover about twice the length of the sensor. Maybe my splice isn't secure??? Would be like running with no O2.

How old is "new"? I had a Bosch unheated sensor go on me at around 3K miles. They're crap, but they're also the only ones carried around here.

aaron_sk wrote:How old is "new"? I had a Bosch unheated sensor go on me at around 3K miles. They're crap, but they're also the only ones carried around here.

Less than 500 miles I think

http://www.thirdgen.org/techboard/exhau ... ut-o2.html

Apparently the harness end of the line wont affect it, but I haven't ever tried it.

I also read earlier today on TGO that new headers can kill an O2 sensor. Can't say as I believe it or not. Mine aren't new, but they are newly coated.

You also have to keep in mind to be extremely careful with the O2 sensors when installing... Any dust, particles, or oils (including from skin) can make the O2 sensor go bad instantly... But checking your wiring would also be a good start.

I unplugged the O2 sensor to keep the car in open loop just to see what it would do. Still have random pops through the exhaust, so I apparently have a leak or 2 I need to track down. My guess is a leak at the collector to y-pipe connection, or one of the 3 A.I.R tubes.

i hate fuel injection and computers.....id say carb it, cam it, new ignition system

smoker wrote:i hate fuel injection and computers.....id say carb it, cam it, new ignition system

Not only would that not solve the exhaust problem, but you'd still have to tune it and you'd be tuning it blind since you have no feedback from an O2 sensor.

BTW, Al, is it running unusually rich? Any time the ECM gets a low or nonexistant signal from the O2 it goes to full rich, which can cause the exhaust to snap. I've had problems with that before.

aaron_sk wrote:
Not only would that not solve the exhaust problem, but you'd still have to tune it and you'd be tuning it blind since you have no feedback from an O2 sensor.
BTW, Al, is it running unusually rich? Any time the ECM gets a low or nonexistant signal from the O2 it goes to full rich, which can cause the exhaust to snap. I've had problems with that before.

It is VERY rich. Maybe then the O2 is bad, I have no way to check it though. I have a new one to put in, but first I'm going to see if I can seal up a leak or two.