LTFT B1 issues, and some knock. NEED HELP PLEASE!
Ok guys this is my first post here. Ive had hp tuners for a few months now and i just traded my turbo truck for a cammed 98 TA. it runs a little rough and definitley runs rich. for some reason my bank one ltft is always pegged idling and cruising. and ive noticed im getting some knock. i cant actually here any knock but i am getting in the scan.

I have no idea what cam is in it. im kind of wondering if i should just get a stock tune back in it and tune it my self. ive never tuned in anything but the walk throughs seem to be pretty on point and tuning for idle with a different cam. i feel like that put a cam in it and either didnt tune it right, or never tuned it at all.

There are no DTCs and no SES light. if they cover the code (check the box) does that mean it wont show up in the DTCs? or just that it wont show a SES light?

BASICALLY ALL THE O2 SENSOR SESs ARE UN CHECKED and a random misfire is unchecked.

Anyway, i would really appreciate some tips and what you guys would do. Im 99% sure i have a couple bad O2 sensors, the question is do i replace them and then see what happens? i would love if some one could find some major issue in the tune that is causing it to run to rich and killed these O2 sensors before i slap some in there and ruin them?

How would you begin to diagnose this? new O2s? or get the tune fixed first? or will i need the O2s working before i can get the tune right? lol

i have a scan i took a little while ago along with the current tune if you guys could look at it that would be great. Thanks

Also if there are any PIDs i need to add or delete from the config let me know please. im not sure what all i need on there

 

After doing some research and comparing a stock tune file to mine it seems like the only codes im worried about are the p0171,p0172 and p0174, p0175 which are

" system to lean/rich bank1/2"
im not sure why they would be set as 3- no error reporting

Like i said i just got the car and now that ive done some more research it seems like those 4 codes are odd to be "no error reporting" and its strange my Bank 1 fuel trim is so crazy.

im not sure why the rear O2s are tuned out because i really thought i still had cats. im going to check out everything under the car tomorrow.

i could really use some help? ANYBODY HAVE ANY IDEAS?

 

Decrease you knock sensitivity. Headers and cam can show false knock.

If it is one bank showing bad ltft I would change your upstream O2 sensor on that bank.

 

ok would i do that in the knock sensor level>Tip in TPS? and if so im not sure how to decrease it. also its an actual "cam only" car haha. Still has stock manifolds and Y pipe.

Were you able to view the scan? and the tune file?

i havent ever had a cammed car but ive been around them alot, the motor rocks quite a bit at idle, seems like more than it should but maybe its normal. im wondering if i need to uncover the 171,172,174,175 and go from there.

is that something that would normally get covered because of a cam swap? Im fixing to order a wideband so i can see whats really going on with my AFR. but just from the smell its running very rich.

 

Verify your coil harness is plugged in on that bank. And make sure your injectors are plugged in.

 

A tune that has the 171,172,174,175 rich and lean codes turned off is a hack tune.

 

This^ I had similar issues. Go over and check all connections

 

ok update time.

i checked resistance on all injectors, all right at 13 ohms

i checked the injectors with a metal rod while it was running, all smooth consistent clicking.

i know every injector harness is plugged in correctly and they were plugged in good before i took them off for resistance test.

coil harnesses are plugged in correctly, i tried to do some research on how to test the coil packs. nothing simple seem to come up with resistance test on the coils.

i changed the drivers side upstream O2 and it didnt do anything, still shows the O2 B1 reading very lean condition which is why i believe the LTFT B1 is pretty much always dumping 20% more fuel in at idle.

i have not checked the plugs yet. But a bad plug would cause a rich condition granted there was fuel getting into that cylinder correct?

Im starting to think maybe a vac leak??? im going to try spraying some carb cleaner around the intake o see if i get any fluctuations in idle. kind of hoping i do.

ALSO. AN THIS COULD BE HUGE OR MEAN NOTHING lol....the drivers side cat is removed and replaced with a piece of exhaust ( which has a leak...) the PASSENGER side cat is still on.


I agree that it was a hack tune. im not sure if it was custom or can tune but either way its not ok with me. My nitrous kit just showed up today and i need to get this crap fix to kill a mustang haha

im just trying to figure out if this is mechanical/electrical or a tuning issue, and being that its only showing the problems in bank 1 makes me think mechanical/electrical. once its fixed i will get it tuned properly.

would you guys uncover those codes and see what it throws....? im sure it will throw drivers side no doubt.

If anyone with good tuning experience could look over the tune and tell me if they see anything crazy that would be awesome

 

Can i just pop the plug wire off at each coil pack to see if anything changes? just like on a distributor?

 

You could also use a infrared temp gun and check the temp on all the exhaust primaries and the one that is alot lower than the rest is your problem cylinder.

 

I'm not a tuning guru, but I would be willing to bet that's your problem. An exhaust leak near an 02 sensor could cause a false lean condition, and that's why its dumping fuel on that bank. Watch your log, when b1s1 reads lean, the fuel trims add fuel.

I would get rid of the other cat and fix the exhaust leak. Make sure the exhaust shop removes the o2 sensors before they weld, if close by.

I'm actually waiting on a new set of o2 sensors for this exact reason. My b1s1 o2 got fried when welding a flange on the header. Reads 0mv and Fuel trims dump fuel...

 

A leak some distance after the O2 may not be an issue, but if at the head, or close to the O2, then yeah it will cause a lean reading.

Are the STFt/LTFT + 20%?

How are the cross counts?

OP, lock the PCM in open loop & see if the idle improves. If it stays the same then the O2 is actually telling you what is really going on. This could be anything including a wiring issue or a bad injector/ driver.

 

Thanks for the tips guys.

The exhaust leak isnt all that close to the o2 but ill get it fixed with my cheapo welder just in case.

Only the bank 1 LTFT is at 20-23%.

Both bank 1 and 2 stfts and and bank 2 ltft are hovering nicely around or at 0.

Im not sure what you are refering to with cross counts. Sorry. Still fairly new at this.

Also im 99% sure their is no thermostat in the car. I cant get this thing to heat up over 170 ish while driving (granted it is 20-30 degrees here right now) but even idling it very slowly climbs to 190, then stage 1 fan kicks on. It was set to kick on at like 175 and i changed that.

Should i throw like a 180* t stat in there?

Thanks for the input on testing to make sure O2 is reading correctly.

I wasnt sure if there was a way to do that. I guess i can just disable closed loop and that will lock it into open loop?

Im starting to think i have an exhaust leak around the back of #7 primary, or inbetween #7 and the O2. I think im starting to hear a whisping noise, maybe its getting worse and starting to show its self, that would be great.

 

Im also confused at how an exhuast leak can show a lean condition.

What am.i missing here? 14.7 parts AIR to 1 part FUEL is stoich, so if you have an exhaust leak before the O2, why doesnt it read rich, because there is less air getting to it now? Ex: 12:1, or 10:1...I know that an exhaust leak does cause a lean condition, im just not sure why and how lol

Also i have tested each injector all at 13 ohms and listened to each injector with a probe, all had nice clean consistant ticking, nothing jumpy or out of place sounding, very uniform.

 

I doubt a T-stat will be effecting what you are seeing on one bank. On the O2 reading lean: An O2 sensor reads just that, O2 in the exhaust stream. A leak, or a mis-fire, will show lean condition. This is because there is more, or residual, O2 in the system.

You can clear the LTFT's & I bet the STFT's will start showing the same unless an O2 was changed & these ere not corrected but over time the LTFT will self correct.

Yes in the scanner tool in HPT you can disable closed loop. Do that first & see what happens.

 

Yea i thought about reseting the trims but i was waiting. I have 6 days off coming up and i can be without the car at that point. It drives pretty good right now. Just idles wierd. But i would still probably be okay reseting it. And still be able to drive.

The drivers side upstream was replaced 2 days ago. Showing the same results.

I am.going to weld the pin hole (s) up that i know are there just to get rid of the noise if nothing. If i have to pull the manifold its deffinitley getting long tubes and a y pipe.

I will try open loop tonight. While trying this im wanting it to idle differently correct? That will tell me the O2s are working correctly?

 

Also im still not sure what the "cross counts" are. Can somebody fill me in on that?

 

Yeah, if it idles better then the O2 is reading something incorrectly.

How is cold start idle? That is a open loop function while the O2's are heating up.

Cross count is how many times over a period of time the O2 sweeps across the stoich voltage, rich to lean & back again, as the PCM alters fueling.

 

Ok thanks for the info.

Im 99% sure my tranny just took a **** soo....thats cool.

SO the $1700 i spent on nitrous wont be used for a little longer lol

Im sure ill have a thread about it soon.

 

O2's sense oxygen. The combustion process consumes that oxygen. If you have a leak upstream you are getting fresh oxygen that hasn't been through the combustion process over the O2's. This makes the pcm think it didn't have enough fuel in the mix, resulting in a lean condition.

People tend to forget that the O2's only detect oxygen. Lots of things can skew the readings coming off them. Spark, cam overlap, leaks etc etc.