"newb question"

[ChanKern]

so, i put long tube headers and OFY... and plugs and wires on my 98' Z28. now when i really get on it, it hit's the rev limiter REALLY hard between 2nd and 3rd... i removed all the 02 sensors and am just running straight off the Y pipe (becuase i live in wyoming and there are no exhaust laws)... what can i do to fix this? mail order tune? or what?

[2002ssslp]

Send you PCM to Steve Williams at Tune by Frost who is a sponsor. Fill out the data sheet and pay the 150.00 you should have your unit back in 4 to 5 days.

[SMWS6TA]

so, i put long tube headers and OFY... and plugs and wires on my 98' Z28. now when i really get on it, it hit's the rev limiter REALLY hard between 2nd and 3rd... i removed all the 02 sensors and am just running straight off the Y pipe (becuase i live in wyoming and there are no exhaust laws)... what can i do to fix this? mail order tune? or what?

The reason you're running like crap is because of several things.

1) Deleting all the O2's not good for a EFI motor. Your pcm needs at least the front two O2 senosrs in order to properly set the fuel trims andread what the oxygen levels are in the exhaust. You need to put these back in.

2) Like Keith posted - get a Frost tune, wakes the car up and he can tune out the rear O2's, adjust the fuel tables and delete the air pump/egr stuff so your SES light doesn't come on.

3) Dumping the exhaust after the ORY - if it's too close you're losing some torque but not HP. Most will dump the exhaust using a E-cut out so you don't have the drone and can control when and where you want it. Usually the e cut out is located just under the rear passenger seat. Nice open spot there.

4) Rev Limiter - What are the rpms at when you hit it? Around 6200-6500 (max) is where it should be set at. V8's do not have high rpm's like the 4 bangers do. Most 4 bangers are in the 8-10,000 rpm range for their max rev limiter. Now there are some V8's that can get higher in the rpm's but they are special cars that have special tunes and cams and such. <<Think NASCAR

[ChanKern]

Thanks for the info... I damaged one of the front o2 sensors when i was removing them, can i use the rear ones in the front? when you say i need the front two, you mean one on each side right? the ones in the collectors on the headers?

[Smittro]

Thanks for the info... I damaged one of the front o2 sensors when i was removing them, can i use the rear ones in the front? when you say i need the front two, you mean one on each side right? the ones in the collectors on the headers?

No you can not use the rears up front..

In a nut shell,,Your front 02's are resposible for telling the PCM what the engines air fuel mixture looks like so that the PCM can make adjustments accordingly.

Even in speed density you need @ least one front 02 sensor.

..and yes you have 2 front 02 sensors, (As your car is OBDII not speed density), in this case in your header collectors, one for each bank of cylinders in your engine.

[SuperSSguy]

No you can not use the rears up front..

In a nut shell,,Your front 02's are resposible for telling the PCM what the engines air fuel mixture looks like so that the PCM can make adjustments accordingly.

Even in speed density you need @ least one front 02 sensor.

..and yes you have 2 front 02 sensors, (As your car is OBDII not speed density), in this case in your header collectors, one for each bank of cylinders in your engine.

I have ''02 simulators'' on my rear 02 sensors..do you know if i can use wide-band 02 sensors and how much they wolud cost?

[Smittro]

I have ''02 simulators'' on my rear 02 sensors..do you know if i can use wide-band 02 sensors and how much they wolud cost?

Can't quote prices, but yes many folks here and elsewhere run wide band 02's to keep track of their AFR's as well as them being a tuning aid.

I'd also ditch the sims,, your rear 02's can be switched "off" with/durring a pro tune.

[Smittro]

This guy here is a good place to start for a great tune and he's inexpensive..

Then,, you will only need to fix your front 02's (and any other issues) rather than buy what can be pricey widebands.

TunedByFrost.com - Professional Tuning For Your LSx Powered Car or Truck

Steve has a good rep for exceptional work and he's fast..

[Too Fast]

All the above, and remember the stock valve train is not designed to exceed 6200 RPM. Bends push rods. Ask any manual trans guy who's put it in 3rd instead of 5th. Yours is an AT car I assume?

[SMWS6TA]

All the above, and remember the stock valve train is not designed to exceed 6200 RPM. Bends push rods. Ask any manual trans guy who's put it in 3rd instead of 5th. Yours is an AT car I assume?

Had that situation at the track last Fri. Had a great 60ft and launch, sweet shift into 2nd and then screwed up shifting to 3rd with a Pro 5.0 shifter. I didn't keep the clutch in long enough to finish the shift. Lost race because I didn't force it into 3rd while in the high rpm range. Rather lose race then blow engine, clutch, rear end, tranny, etc.....

[SuperSSguy]

This guy here is a good place to start for a great tune and he's inexpensive..

Then,, you will only need to fix your front 02's (and any other issues) rather than buy what can be pricey widebands.

TunedByFrost.com - Professional Tuning For Your LSx Powered Car or Truck

Steve has a good rep for exceptional work and he's fast..

I may be duplicating what i wrote on another thread but Its to my understanding you have to send in your PCM for a Frost tune? I live in Calif, in a ''enhanced'' smog area! meaning we have bi-annual smog tests. With my handheld im able to re-load my factory tune for the emmisssion test then after re-load any enhanced tune i have stored. Im wondering how i`d be able to do this with a Frost tune ?

[Smittro]

I may be duplicating what i wrote on another thread but Its to my understanding you have to send in your PCM for a Frost tune? I live in Calif, in a ''enhanced'' smog area! meaning we have bi-annual smog tests. With my handheld im able to re-load my factory tune for the emmisssion test then after re-load any enhanced tune i have stored. Im wondering how i`d be able to do this with a Frost tune ?

Oh I see,, hmm well I can't say in that instance..

Ya you have to send it to him, he also sells PCMs' too iirc.

Other than that,, damn' Cali! jk

[SuperSSguy]

Oh I see,, hmm well I can't say in that instance..

Ya you have to send it to him, he also sells PCMs' too iirc.

Other than that,, damn' Cali! jk

Tell me about it!! We are screwed When it comes to smog and emissions! We are very limited I hate it and am so envious of ''other'' states that allow almost anything! We have beautiful weather,beaches,mountains cars and women!! etc. Guess you cant have it all!!

[Smittro]

Ya, we still have it somewhat good here in Steeler Nation, they started visuals a few years ago in rural areas which is bs.

Cities are real tight on it..

The vehicle has to "appear" to have all it's emissions componets in rural areas..

But there are loop holes, grand fathered in too, and if we stay under 5000 mi. per year we are emissions exempt.

[ChanKern]

I'm searcing for new O2 sensors and none of them seem to say if they are front or rear... i took the old O2 sensors out of the exhaust i took off the car and the front and rears look identical.

[SuperSSguy]

Ya, we still have it somewhat good here in Steeler Nation, they started visuals a few years ago in rural areas which is bs.

Cities are real tight on it..

The vehicle has to "appear" to have all it's emissions componets in rural areas..

But there are loop holes, grand fathered in too, and if we stay under 5000 mi. per year we are emissions exempt.

Yup! We have stages the visual is one that basically is up to the tech.Alot of them just look and see my Lt`s and say goodbye! cant help you! Some look the other way and focus on the cats..thats mandatory we have to have cats with an E.O. # (executive order #),Then the ''functional" test and then the actual ''sniffer'' test now run on a dyno type machine to simulate road conditions first @ 25mph ( like anyone goes 25) then the 45 mph. Often times the slower 25 mph is the one that`ll get ya! We have it rough here!! That is unless you have boat loads of money to spend and inatead of trying to get HP with mods you just get a high dollar muscle or exotic with 500 to 650 Hp stockl!

[Smittro]

Yup! We have stages the visual is one that basically is up to the tech.Alot of them just look and see my Lt`s and say goodbye! cant help you! Some look the other way and focus on the cats..thats mandatory we have to have cats with an E.O. # (executive order #),Then the ''functional" test and then the actual ''sniffer'' test now run on a dyno type machine to simulate road conditions first @ 25mph ( like anyone goes 25) then the 45 mph. Often times the slower 25 mph is the one that`ll get ya! We have it rough here!! That is unless you have boat loads of money to spend and inatead of trying to get HP with mods you just get a high dollar muscle or exotic with 500 to 650 Hp stockl!

Yeah Wa. ran the dyno tests back when I lived in Seattle. Would'nt give you your plate tags if you did'nt pass..

Stupid setup if ya ask me..

Back here in Pa. only OBD1 cars get the sniffer.

OBD2 get's a log reader. If your service engine light is on they won't even touch it.

We have state inspections and we can't get our inspection sticker for the windshield without first passing emissions then a safety check..

Another dumb setup imo. No loop holes in the city unless you know people and then it's a huge deal if they get caught.

So I keep something newer in the stable as a DD and the mileage down on the toys.

[Too Fast]

I like how they give you the loop hole about driving less than 5,000 miles per year. One could have several play cars that way, if you had $$$ for them.

[Smittro]

I'm searcing for new O2 sensors and none of them seem to say if they are front or rear... i took the old O2 sensors out of the exhaust i took off the car and the front and rears look identical.

Do all 4 connectors look like this?



If so check your part numbers, I believe the fronts are different.

[blackcar]

I'm searcing for new O2 sensors and none of them seem to say if they are front or rear... i took the old O2 sensors out of the exhaust i took off the car and the front and rears look identical.

Get a pair of Bosh 13111. They are for the Corvette and have a longer wire. The wire for the stock ones on our cars normally won't reach the collector in the header.

Probably get them cheaper on ebay than a local parts store.