DYNO numbers: car running rich
- Thread starter sjrtx
- Start date
Red35th
Member
My god, you are going to foul your plugs.
You definatly need a chip (or see my thread on the TwEECer, much cheaper/better).
With your a/f that rich you are losing over 10hp. Noone tunes blower cars that rich.
Invest in some sort of tuning device.
I'm not sure why your car is running so rich, but I would spend my next paycheck on a chip.
You definatly need a chip (or see my thread on the TwEECer, much cheaper/better).
With your a/f that rich you are losing over 10hp. Noone tunes blower cars that rich.
Invest in some sort of tuning device.
I'm not sure why your car is running so rich, but I would spend my next paycheck on a chip.
cap42
New Member
Your losing alot more power than that 230hp? I'd say it's your LT's with teh 75mm TB your running a catless midpipe you have MIL's that are working?
Get a tune like NOW with your mods you should be at least 15rwhp higher
Get a tune like NOW with your mods you should be at least 15rwhp higher
anyone else have the same mods-and run rich?? what else could be causing it to run so rich? i think its making an o2 sensor go bad. i left the shop right after the dyno, and the check engine light came on. stopped at autozone, had them read the code. said sensor 1 bank 2 was slow responding. The mil eliminators are on the back two o2 sensors-after where the cats would normally be. Its my understanding, that the computer doesnt get its reading from those, it only detects if the cats are working or not. They told me, that the code they were getting was the front driverside o2 sensor.
jstreet0204
Active Member
sjrtx said:
You don't need a tune with your mods I've got pretty similar mods and even without a tune, my A/F was pretty close to 13:1. The tune just smoothed it out. You've got a problem some where else if you are running that rich. I am surprised your CEL hasn't come on. Have the codes scanned anyway and see if any show up.
the check engine light did come on, but after i left the dyno shop. it said that sensor was having issues. now-ive had the car for 4 months now, and this is the first time this light has come on. now...is it an o2 sensor causing it to run rich, or is it running rich causing an o2 sensor to go bad?
jstreet0204
Active Member
sjrtx said:
Could be either way. If you want to avoid buying a new one to be sure, try switching the rear one to the front and see if it leans up some. I have done that in the past just to verify it was the o2. If it is, it is a good idea to go ahead and buy a new pair for the front.
ok, well i went and replaced the o2 sensor that was supposedly giving me problems, drove it around a LOT, and just when i thought everything was ok, the damn check engine light comes back on. My guess would be o2 sensor again. Ill have to get it checked in the morning. Could a rich condition cause these things to go bad? Or by these things going bad, is it causing me to run rich? I only replaced 1 sensor-i dont know yet which one its going to be. anyone have any clue?
Obviously, something is causing the car to run that rich in open loop. The first thing I would do is what was stated before - swap the O2 sensors from the back to the front (changing the harness obviously). I would also reset the PCM. Disconnect the battery and turn the headlights on - leave it for a couple minutes to kill the keep alive memory.
Here is just a thought: The PCM will apply a corrective factor to the a/f based on the O2 reading. If the a/f is still out of range when the PCM exceeds the maximum allowable correction it will throw a CEL.
Here is just a thought: The PCM will apply a corrective factor to the a/f based on the O2 reading. If the a/f is still out of range when the PCM exceeds the maximum allowable correction it will throw a CEL.
newest update:
Went and got the code checked-and this time it was the other o2 sensor-1st one on driver side-just replaced the 1st on the passenger side. SO i did that, cleared the pcm, which cleared the light. First thing i did (besides letting the car idle with and without a/c for a little bit) was go back down to the dyno. 3hp more-car still running rich. Then the guy burned a SCT chip with a standard tune-plugged it in, and almost the exact same number-233hp and 271 torque. Car was still running rich. It was actually a little richer at idle with the SCT chip, but as the RPM's went up-the a/f started dropping from 13 to finally 11:1. Sooo....i guess im going to go spend some cash on a custom tune tomorrow with a diablo chip-$500 is what its going to cost me. But that will be on a dyno with a/f. Car isnt throwing any other codes....so i guess we'll see what happens.
Went and got the code checked-and this time it was the other o2 sensor-1st one on driver side-just replaced the 1st on the passenger side. SO i did that, cleared the pcm, which cleared the light. First thing i did (besides letting the car idle with and without a/c for a little bit) was go back down to the dyno. 3hp more-car still running rich. Then the guy burned a SCT chip with a standard tune-plugged it in, and almost the exact same number-233hp and 271 torque. Car was still running rich. It was actually a little richer at idle with the SCT chip, but as the RPM's went up-the a/f started dropping from 13 to finally 11:1. Sooo....i guess im going to go spend some cash on a custom tune tomorrow with a diablo chip-$500 is what its going to cost me. But that will be on a dyno with a/f. Car isnt throwing any other codes....so i guess we'll see what happens.
jstreet0204
Active Member
I would not put the money into a custom tune yet!
Eliminate other things first, because something is wrong. If the o2's are good check the MAF next, check the TPS, AIC sensor, and the fuel pressure sensor. Those are the only things I can think of off the top of my head that would effect the a/f during open loop (WOT). A tune could possibly fix the problem, but if it does you are going to have to get another tune once you fix the real problem, because the tune was set with bad sensor information.
Eliminate other things first, because something is wrong. If the o2's are good check the MAF next, check the TPS, AIC sensor, and the fuel pressure sensor. Those are the only things I can think of off the top of my head that would effect the a/f during open loop (WOT). A tune could possibly fix the problem, but if it does you are going to have to get another tune once you fix the real problem, because the tune was set with bad sensor information.
jstreet0204
Active Member
sjrtx said:
Bad sensors won't always throw codes. The best way to find out if everything is working within range would be to find someone that can datalog from the computer, with something like an autotap.
jstreet0204
Active Member
jstreet0204
Active Member
wms004
Founding Member
