Just bought a 95 stang and had some questions

[sj9ers]

So I just bought a 95 gt 5 speed with some shorty headers and straight pipes and 3.55 gears and a BBK air intake installed. The previous owner said it had bad 02 sensors that needed to be replaced and I figured that was the case because I've been driving the car and I've been getting the check engine light and horrible gas mileage. So I installed some new sensors today and let the computer reset by disconnecting the battery for half an hour. On the car theirs a cheap Sun pro air fuel ratio gauge like this http://www.tradervar.com/ImagesCache/Electrical-Air-Fuel-Gauge-CP8210-Sunpro-I21031.jpg hooked up. Before I replaced the 02 sensors it would only work sometimes and mostly either read lean or rich or not work at all. Now that I replaced the 02 sensors reset the computer and hooked the gauge back up it will start out at lean then move to ideal for a little bit then to rich and then just start bouncing back and forth erratically. I was wondering how accurate is this gauge and should I just disregard the readings its giving me? And right now the car is idling at or a little below 1k rpm. Is this normal?


And if anybody is at or around San Jose, CA and can help me look over the car to look over the car and offer some help or advice on what I need to on the car since I'm kind of lost on it considering I've been working on engines with carbs that would be great.
Thanks

 

[NinJa_FLiP]

if i were you, id get rid of that gauge.. might be cool for looks, but is terrible at reading air/fuel ratios.. rpm below 1k is normal, so no worries there.. and by straight pipes, you actually mean no cats and no mufflers? man that must be loud.. lol

 

[sj9ers]

if i were you, id get rid of that gauge.. might be cool for looks, but is terrible at reading air/fuel ratios.. rpm below 1k is normal, so no worries there.. and by straight pipes, you actually mean no cats and no mufflers? man that must be loud.. lol

Ya I'm planning to get rid of it but the previous owner put some horrible glue behind it on the a pillar to mount it. Ya no cats or mufflers lol but it gets everyone's attention including cops which is why a new exhaust system is going on with my tax refund lol.

 

[NinJa_FLiP]

well, g/l to you.. and make sure u get emissions friendly parts since CA is a pain in the arse with their smog.. thats one thing i dont miss about cali.. lol

 

[Tom95gt]

So is it running right after you did the 02 sensors? Those gauges are useless without a wideband. I would also do plug wires because that will kill gas mileage too.

 

[ProKiller]

if i were you, id get rid of that gauge.. might be cool for looks, but is terrible at reading air/fuel ratios.. rpm below 1k is normal, so no worries there.. and by straight pipes, you actually mean no cats and no mufflers? man that must be loud.. lol

+1

that gauge is useless for anything but a pretty light show.

 

[sj9ers]

+1

that gauge is useless for anything but a pretty light show.

Agreed. Now that I replaced the O2 sensors the thing works now and its annoying as hell.

 

[HankyGT]

You guys crack me up sometimes.

Lol...those style gauges are pointless yes; but because it's designed for a narrow band 02 sensor. What you are seeing is the car is in open loop mode and cold with a constant a/f reading + the fact that the sensor is still cold. Once the car/sensor is at temp, the ecm goes into closed loop and the MAF is making constant corrections. Since a narrowband operates at only a few .tenths of a volt range; the gauge will just sweep back and forth at idle and cruise as the computer corrects. You will see the same with a wideband too, but in digital format. What makes the narrow band useless is that it is very hard to pinpoint an actual a/f # as the sweep of voltage measurment is too short, and is only an immeasurable green light at WOT when it's actually a constant and buried in the 'rich' somewhere.

The gauge is not faulty, but you need a wideband gauge/sensor/driver to accurate tell whats going on. Also, that guage is only going to be triggered by one of the 02 sensors; so the fact that it is sweeping means that the 02 sensor used is cycling (as long as it's not very slow sweeps), but you are neglecting to see if the opposite sensor is coming online.

 

[NinJa_FLiP]

yea, took the words right out of my mouth!!! lol