running rich

**ssdreamz** · 04-03-2007, 04:01 PM

my younger brother has a 98 camaro Z28. his mods are pacesetter headers ORY pipe (no cats) magnaflow catback, gears, O2 sims, SLP flopac. he has pretty much a stock tune. well he got a SES light. bank 1 sensor 1. so a O2 sensor went bad. its since been replaced and the code cleared. now for some reason, its been running rich.... when he first jumps on the throttle, he puffs black smoke, at high rpm shifts, he even shoots a flame out of the exhaust. he says now his gas milage has went downhill. what could be happening here?

**kealap** · 04-03-2007, 04:08 PM

did you use a cheap bosch replacement sensor from the auto parts store or a delco? Makes a BIG difference.

**ssdreamz** · 04-03-2007, 04:11 PM

actually he used an original O2 that came out of a 99Z28 that was wrecked...my neighbors

**ssdreamz** · 04-03-2007, 04:11 PM

what sensor brand should he buy?

**PFM** · 04-04-2007, 07:03 AM

I would pull out the O2 sensor you got from your neighbors car and get a fine copper wire brush and give it a good cleaning up and reinstall it. I've seen this work twice might be worth the trouble. Thoses sensor ends need to be clean.

**kealap** · 04-04-2007, 07:59 AM

Probably best to buy a NEW AC delco sensor. Either from the dealer or a parts store. The parts store will prob. have to order it in though. Most don't stock delco parts.

**GottaHaveLS1** · 04-04-2007, 11:24 AM

Originally Posted by kealap

did you use a cheap bosch replacement sensor from the auto parts store or a delco? Makes a BIG difference.

I thought Bosch parts were good. I replaced two of my 02 sensors with Bosch a while back and they're fine.

**GottaHaveLS1** · 04-04-2007, 11:27 AM

Originally Posted by ssdreamz

my younger brother has a 98 camaro Z28. his mods are pacesetter headers ORY pipe (no cats) magnaflow catback, gears, O2 sims, SLP flopac. he has pretty much a stock tune. well he got a SES light. bank 1 sensor 1. so a O2 sensor went bad. its since been replaced and the code cleared. now for some reason, its been running rich.... when he first jumps on the throttle, he puffs black smoke, at high rpm shifts, he even shoots a flame out of the exhaust. he says now his gas milage has went downhill. what could be happening here?

sorry to change the subject but i have the same mods minus the gears, pacesetters & ory. I plan on getting the pacesetters and ory, do you think it sounds raspy at all?

**ssdreamz** · 04-04-2007, 01:02 PM

doesnt sound raspy at all, actually it is quit mellow until he hammers on it

**GottaHaveLS1** · 04-04-2007, 01:18 PM

Originally Posted by ssdreamz

doesnt sound raspy at all, actually it is quit mellow until he hammers on it

hmmm, good to hear. I saw a clip on ls1sounds.com with a z28 that had jet hot lt's, ory and magnaflow. whenever he let off the gas it was really raspy and sounded like shit.

**Wheeler99WS6** · 04-04-2007, 05:20 PM

After Lt headers the general consensus is that our cars run a little rich at WOT (wide open throttle). The PCM will strive to keep the air to fuel ratio at stoich (14.7) during idle and part throttle. Fuel trims at WOT go off the Maf table I believe. So tuning will yield you the most hp gains possible and can clear up any related problems while at WOT.

**tblu92** · 04-04-2007, 07:02 PM

You used a 99 02 sensor on a 98 ??? Probably not the right one---

**ssdreamz** · 04-04-2007, 07:05 PM

actually i was wrong it was his own rear O2 sensors that he deleted but kept the sensors

**0rion** · 04-05-2007, 08:24 PM

I would replace the sensors and get a tune. Running rich will foul O2's over time. I think there should be a law written that states if you mod your car it's required that you purchase some type of logging software. If he were to log the car it would tell him and others exactly what's going on with the car.