Running rich, help.

[sleepyalero]

Well probably about 2 weeks ago my AEM wideband started saying I was running rich between 65-75mph. (Cruising) any speed under, or above it runs "starch". I went to autozone and asked them and told them what's done motor wise. They said I possibly need to upgrade my MAF.

Yet, I can't tell if it's just my gauge false reading or its actually the car. The car doesnt feel like its running rich, doesn't bog at that speed or anything. But at night when driving... I can see numbers on my AEM gauge kind of dim, then brighten up every so often, which makes me wonder the gauge could be false reading...

Recent mods/fixes

- 65mm TCE TB.
- MMS ported/polished UIM/LIM.
- universal o2 sensor which was wired up to a stock plug. (Possibility for running rich?)

What it has/had for some time now.

- headers
- CAI
- EGR delete
- no cat

Few other things..

But I bought fuel system cleaner because i feel it's needed so why not. Autozone also told me to try it first (was going to get it either way) and see what happens after. I will probably fill my tank and dump it in tonight to see what happens.


If a bigger MAF could help? Could I buy an LS1 MAF slap it on and go? Or do I need some tuning for it to work right? I've tried an ls1 MAF about 4 years ago when my car was more stock, and the car didnt like the change.. Don't know if it would now since I'm running more air into the motor now.

When i told the autozone guy about my bigger tb and ported UIM/lim he asked if I was running stock MAF I said yes, and he suggested that could be it because the more air flow, he suggested a GTP MAF and i said well most alero guys go for the LS1 maf's he said that will also work. Any insight would be appreciated.


Don't know if at ass someone could hook up HPT and go for a ride with me to tell me if it is the car or the gauge being stupid. And if the car, maybe a little tuning could help?


Thanks guys.


Oh also, like i said it started about 2 weeks ago. The car did not do this after the UIM/lim change or the TB upgrade.

[Mike The Canadian]

Have you noticed anything else with the way it runs?
You're not at the level that you'd need to upgrade your MAF..
The big boys running fully built motors generally don't max their MAF; that's for the boosted boys.

It's possible that there's an exhaust or intake leak (they'll cause this).
How's your idle?

[sleepyalero]

i figured so on the maf, but wasnt sure.

car accelerates well, idles like normal, no running rough or anything, like i said, it runs fine at any speed cruising or accelerating, and at idle, only at 65-75mph the gauge tells me im running rich. which kinda makes me wonder if its just the gauge. but its hard to tell since i dont have HPT

[Mike The Canadian]

True...

Is it a wideband or narrow band?
With a narrow band what it's reading may be normal..

[sleepyalero]

wide band, 14.1-15.9 is normal. anything before 14.1 is lean, anything after 15.9 is rich.

its also got the bars that hop around the digital numbers, so 14.1-15.9 is yellow. before 14.1 is green, and after 15.9 is red.

[Shiwnath]

If it doesn't smell like you're running rich, no check engine light, no change in performance or bad gas mileage I'd say its just your gauge.

Also you need to change your MAF tables in your tune in order to run a different MAF. Different MAFs aren't interchangable without a tune first.

[sleepyalero]

If it doesn't smell like you're running rich, no check engine light, no change in performance or bad gas mileage I'd say its just your gauge.

Also you need to change your MAF tables in your tune in order to run a different MAF. Different MAFs aren't interchangable without a tune first.

thank you. no smell either, and no to everything else, cant believe my gauge is already messing up, bought this almost a year ago new for 180$ wtf!!! :lol: i even tried re wiring it, seemed to work for a day, then it started reading wrong again. could i possibly clean whatever gunk is on the end of the o2 sender to see if that would help? (for the gauge)

also putting fuel cleaner in it soon, see what happens with that.

[tw0123]

any warranty on the gauge? if it's a 1 yr warranty, call them up and exchange it... if you can warranty it, save the stress and change it first at no cost, then problem solve if the new gauge still gives those readings...

[sleepyalero]

well sadly, i bought it new off a gagt member.

[sleepyalero]

okay update, tell me what you think, gauge or car?


so i went on a good drive, got up to 65 mph set cruise, car ran normal (from looking at gauge) for a good.... 15 miles? or a little less? then started running rich. so i let off, went down to 55, and back to normal. set cruise again, slowly went up to 65 mph hitting the accel button. so... 55 mph wait a min or two, then hit it, 56mph, wait then 57 mph, so on to 65 mph. once again at 65 was running fine, then after about 15 miles again, it started to run rich.

now does that seem like a bad gauge or the car? once again, i see no signa of the car actually running rich, idling fine as im typing this in a parking lot, no service light, no bogging, nothin. in 6th gear i can put the pedal to the floor and it will accelerate pretty well. rpms are steady no matter what, its just annoying to see the gauge in the red zone, i hope its the gauge and not my car.

[sleepyalero]

this would be so much easier if i had HPT, sigh..

[sleepyalero]

sorry i have it wrong, the car runs lean (red zone) not rich. im an idiot

[AleroB888]

Well probably about 2 weeks ago my AEM wideband started saying I was running rich between 65-75mph. (Cruising) any speed under, or above it runs "starch". .

Well, there's your problem, you need to avoid starchy fuel

[sleepyalero]

Well from my understanding the "yellow zone" 14.1-15.8 on the wideband means it runs "starch" or normal.

[AleroB888]

But seriously, folks....

I'm going to go out on a limb and say there's nothing wrong there. Not that there's always room for improvement.

drive it down and I'll scan it with HP, then we'll run it at Ohio Valley

[a.graham52]

Do u have an ultra gauge? What r ur fuel trims in conjunction with ur wideband?

[xXManwhoreXx]

Starch llololol stoich bro

[Mike The Canadian]

I have you have a tune (which I thought you did) it could be your car going into "lean cruise" mode or whatever they call it for fuel consumption?

I wouldn't worry too much, although I like you watch my gauges like a hawk and it drives me nuts when they're not right!!

[jackal2000]

So you are flowing more air with those mods, but have not added more fuel with a tune so I totally believe it is leaning out. My PowrTuner might be for sale soon.

[xXManwhoreXx]

No gauges for me just listen to her man. If she's sick she will tell you...

[Mike The Canadian]

So you are flowing more air with those mods, but have not added more fuel with a tune so I totally believe it is leaning out. My PowrTuner might be for sale soon.

I don't think it would be leaning out that bad.
Before I got my tune done my car was still running spot on after a few weeks of the mods.

The car uses it's sensors to figure out what to do fueling wise and should adjust.
That being said, you don't get as much out of things without a tune!

[04PONTIACGA]

Couldn't he possibly have a vacuum leak(LIM or UIM gasket leak) that would cause it to run lean?

Considering he just did P&P manifolds, there may be a leak somewhere and if the air is getting in after the MAF this would cause a lean reading, right?

[sleepyalero]

But seriously, folks....

I'm going to go out on a limb and say there's nothing wrong there. Not that there's always room for improvement.

drive it down and I'll scan it with HP, then we'll run it at Ohio Valley

tempting lol :)

Do u have an ultra gauge? What r ur fuel trims in conjunction with ur wideband?

i do not :(

Starch llololol stoich bro

facepalm....

I have you have a tune (which I thought you did) it could be your car going into "lean cruise" mode or whatever they call it for fuel consumption?

I wouldn't worry too much, although I like you watch my gauges like a hawk and it drives me nuts when they're not right!!

im glad you know how i feel lol

So you are flowing more air with those mods, but have not added more fuel with a tune so I totally believe it is leaning out. My PowrTuner might be for sale soon.

well i would figure the computer would learn okay more air coming in, lets add more fuel. and yeah? how much,

Couldn't he possibly have a vacuum leak(LIM or UIM gasket leak) that would cause it to run lean?

Considering he just did P&P manifolds, there may be a leak somewhere and if the air is getting in after the MAF this would cause a lean reading, right?

possible.. but it only does it in a 10 mph radius. so im not sure.

[sleepyalero]

alerob888 if you really want to i could head to KY early this week maybe and maybe we can do some adjustments?

[AleroB888]

alerob888 if you really want to i could head to KY early this week maybe and maybe we can do some adjustments?

I would not mind doing that, however I would only be able to read the PCM file and log some scans, but not change the file. I can probably get the licence beforehand for your PCM from HP Tuners, if it is not a custom file.

It is possible Milzy has parts of your PCM customized which should not be changed, or may have the file locked. Better get Mike to authorize it first.

[sleepyalero]

well i have a license thru HPT but i foget all my log in info and stuff....


i dont think mike would lock anything, ill ask to make sure. pm me your address so i can see how far of a drive it is please maybe we can meet up this week

[sleepyalero]

think a new fuel filter could help? been awhile since i have changed that.

[AleroB888]

well i have a license thru HPT but i foget all my log in info and stuff....


i dont think mike would lock anything, ill ask to make sure. pm me your address so i can see how far of a drive it is please maybe we can meet up this week

Well, Mike may have some proprietary custom files in there, which are a lot of work to develop, especially for the trans. There are some PCMs that won't allow scans, either. I was not able to read or scan one of the SCT concept cars some years ago (it had the 4T65E trans) back in CO.

I can try to scan yours, but that's a long drive just to find out, lol

Indy to Ft. Knox

[sleepyalero]

yeah that is true, i texted milzy, waiting for a reply, you think a fuel filter would help at all?

[AleroB888]

yeah that is true, i texted milzy, waiting for a reply, you think a fuel filter would help at all?

It wouldn't hurt, but I don't think it relates to what your seeing there.....

[sleepyalero]

well i googled what makes a car run lean, fuel filter is a possibility apparently. 12$ fix couldnt hurt especially since this one is 2-3 years old i think

[Mike The Canadian]

Yup go ahead and change it.

Does the car run lean at WOT? That's where a fuel filter would start to cause problems. It's still not a bad idea to change it frequently, especially since it's clearly not the 1st time you've done it!

[sleepyalero]

No car runs well at WOT. Just cruising at 65 after a few.

[AleroB888]

so i went on a good drive, got up to 65 mph set cruise, car ran normal (from looking at gauge) for a good.... 15 miles? or a little less? then started running lean. so i let off, went down to 55, and back to normal. set cruise again, slowly went up to 65 mph hitting the accel button. so... 55 mph wait a min or two, then hit it, 56mph, wait then 57 mph, so on to 65 mph. once again at 65 was running fine, then after about 15 miles again, it started to run lean.

....

If you put it in cruise, a PCM can modulate speed by changing spark or shifting gears. It can't shift with a manual of course. Sometimes the PCM will command the AFR higher in some modes of cruising. So you need to monitor "Commanded AFR" to see if the PCM is going lean by design.

[sleepyalero]

so i need to bascially hook up hpt and see what its saying? and not look at the gauge?


i just did a fuel filter on the car about to test drive on highway see if it still occurs. be back soon with updates

[AleroB888]

so i need to bascially hook up hpt and see what its saying? and not look at the gauge?
..

You would compare "AFR Commanded" to what you read on the gauge, that would tell you if it's normal operation for the PCM. You have to trust the gauge for the time being, especially at WOT.

[sleepyalero]

the fuel filter did not fix the problem, seemed to help a little but still shows on wideband im leaning out.

[sleepyalero]

You would compare "AFR Commanded" to what you read on the gauge, that would tell you if it's normal operation for the PCM. You have to trust the gauge for the time being, especially at WOT.

yeah, at WOT what should the AFR be reading?

[AleroB888]

yeah, at WOT what should the AFR be reading?

My 2003 stock V6 scanned from 13.1 at a standing start WOT run, and reached 12.4 at about 75 mph. That was "AFR Commanded."

However, the actual AFR most likely got leaner. I don't know, because there was no wideband set up on it.

[Redog]

Took Redog to the track today (Sunday) and I've been having a lot of problems with it running lean.

Got one good run and at WOT it ran at 12.2-12.6 the entire track. The other two times, yeah let's not talk about that.

I'm running a LS1 MAF, but I think that's a big part of my problem after looking at some tunes on the HPTuner's tune bank. Considering one guy with more work done to his car (hot cam, bored out) has Delta Flow Postive and negitive flows at 0.3 to 0.6 and mine is at 66.141 :eek:

[sleepyalero]

right on, aaron basically told me the same thing on gagt. he suggests o2 as i was kind of thinking it could be a possibility. he said if the car leans out at cruise, but is under 13.4 at wot (i run 13.1 at wot) he said an o2 is most likely the problem. so i will replace it in the morning and report back after for an update.

nice thread jack ken!! haha jk, lot of good help and info in this thread, get the help you need. but dont forget about me as well for help! hahaha.

[RalphP]

On a steady cruise, what MAY be happening may be EGR is being commanded on.

On a steady cruise, it may be the ECU is leaning the AFR out to increase gas mileage. Which is fine as long as something is done to prevent preignition (like a bit more aggressive knock handler, etc.)

RwP

[sleepyalero]

my egr is removed/tuned out. :)

im here to update. the problem is fixed!!! went to autozone, bought a normal bosch o2 sensor, removed the old bosch universal o2 i had in there parking lot, installed new o2 with a casper electronics 6" extension plug for it so it would reach the plug at top of motor, (only reason i bought the universal cause of longer wire so it reached) went on a oh... 25-30 mile drive cruise set at 65mph, didnt go lean the whole drive. thank you everyone, glad this problem is finally solved! i can finally sleep at night knowing the car is in good running order.

now onto ken's solution.... :lol: