houston

Victor, I know that feeling with the 295 rears wiggle. It feels awesome.

So, is she faster than a cheetah on coke?

Great writeup! Glad to see you have experienced the installs first hand and be able to give others the view on the installs. Now just don't get too addicted to mods and power. I know it's just kicking in. You've already made me feel the need for more power just by giving your experiences with the beast after these mods. Keep up the good work and we wanna know more as you progress.

BenzoBoi

Im jealous ... LOL

DerekFSU

Cool. Now get ye to a track.

vrus

Dyno guy called me back.. he said he still has to break ground at the new location and cement in the dyno... DAMN! He wont be up and running for 2 weeks.. Gotta find another place with a dynojet to do another pull now.

Indeed she is!

Ahh.. Just call John and order a set for yourself and join the 2 man club.

That to is coming. Gotta make a run up to Cayuga Dragway Park and see if I can click off a good run.. Problem is they are really strict up there from what I hear.. They kick people off if they break into elevens... Dont really want to drive 1.5hrs one way just to get 1 run off...

DerekFSU

Ask them what rules they follow. They used to be NHRA track and NHRA rules were changed due to the upgrades in street car safety. Current NHRA rules require a rollcage at 11.49 and below.

pokerFACE

this poster looks familiar, and the car looks familiar. what gives?

Marcus Frost

Vrus,

Great write up my friend. I'm doing an exhaust setup that I think should really be pretty wicked, but it's basically a modified stock system, not a new bolt on unit. With it, I think even you would gain quite a bit more hp.

I'll save it for now, going tomorrow to put her up and take some final measurements, then later in the week or early next week we'll get to work on it. I think it's going to be wicked and sound sick as well.

-m

vrus

Hey Marcus,

Where you been buddy? Yeah.. The exhaust has been bugging me for a long time. I know if I get rid of those 2 cantelopes just below the headers it will wake this thing up BIG TIME.

I keep getting told to not take off the first 2 cats because it will cause a check engine light.. If that's the case, then how the heck do the kleemann headers do away with the cats without re-routing the position of the O2 sensors? I mean, if Kleemann can replace the cats and not get a check engine light then I should be able to... Or am I missing something here?

Did you end up picking up those high flow cats? I had the random tech on order but I cancelled them because I wasnt sure about the check engine light problem.

What do you think?

Can't wait to see what you come up with... Make sure you share..

darren_dallas

Victor,

When Kleemann installs their headers they move one of the O2 sensors from just after the CAT to a place on the collector of the header. Then they specifically disable the ecu's code that checks for the first CAT. This is how they eliminate the check engine light issue.

Cheers,

Darren

vrus

Hey Darren,

I appreciate the input.. But, it is still confusing to me because when I was looking at buying their headers I remember I specifically asked Cory if I could bolt them in and not have any issues with check engine light or anything else. He told me there was no check engine light issues. Remember, I never wanted to get the ECU REPROGRAMMED, I was only going to buy the headers.

How, in this scenario, do they sell just their headers to a customer and not have issue with check engine light? I know that the header package is only headers and downpipes. They dont provide O2 simulators or anything else like that.

From what I remember from standing beneath my car, we have 1 O2 sensor just before the primary cat, and we have 1 O2 sensor just after the primary cat.

darren_dallas

Victor,

All good questions. Here's what I can tell you from my installation in July. After Kleemann installed the mods (ecu, pulley, and headers) my wife and I left the Kleemann facility. About 30 miles or so later the check engine light came on. We drove back to Kleemann the next day and we hooked up the OBDII cable to the car and then Cory used his software to remove the light and configured the car to not check for that specific O2 sensor.

This is not as invasive as modifying the ecu in the regular manner (desoldering it from the ecm, then updating the rom, then resoldering the ecu back). This was done by a simple OBDII change.

Hope this helps. This is about the extent of my knowlegdge on this topic. I don't see how the check engine light wouldn't come on after installing the Kleemann headers and removing the primary cats. The light will come on unless you remove the code that checks for it.

jparch

Victor , the purpose of the downstream o2 sensor is to monitor the effieciency of the converter in front of it. Unless you "trick" the computer after removing the cat you will continually get a O2 sensor efficiency code.

vrus

Hey John,

Yup. I know... That's why I am so confused on how Kleemann can sell their headers to a customer who DOESNT want to reprogram their ECU and not supply anything to compensate for the catalytic converter not being there any more.

darren_dallas

Victor,

I'm not sure Kleemann will without asking for your ecu, unless you're fine living with the check engine light on all the time.

Regards,

Darren

vrus

I will have to talk to Cory and see because I know I was specific with him and Brandon when I was looking at buying the headers from them. I asked point blank about the check engine light and I was told there was no check engine light to worry about. I was quoted $3,600 for the headers and that is all I was going to buy at the time.

Now you know why I am scratching my head on this one.

vrus

Wicked... Booked an hour of dyno time tomorrow night at 5pm. Will be bringing my datalogger with me so I will do datalogs of all the runs.

I should have some hard numbers tomorrow night on the upgrades I did and how well they affect efficiency of the car.

Stay tuned...

JamE55

^^ Don't forget to take some pics!

vrus

Pics on the dyno? Nah... car is way too dirty to be photographed.. Havent had time to clean it up since last time.. No pics this time.. Just data.

Marcus Frost

Victor,

The reasoning is simple - the first O2s aren't *really* looking for any catalytic performance, they are looking for the A/F ratio. The 2nd one then is looking for an osciallting difference value between the #1s ratios to make sure that the 2ndary cats are doing their job. This is a very simplified breakdown, but it's pretty accurate.

The precats (that is, the ones before the first O2 sensor) are relatively useless in terms of emissions monitoring (unless you get pig rich or something to that effect) and the ECU doesn't really give a crap about them, thankfully. The 2nd ECU is looking for a certain amount of catalytic converter activity and it takes a certain sized (cell count) catalytic converter to achieve this. The best setup is knowing the minimum amount of cells the cats need to have (which is a LOT less than what the huge factory ones have) and use that in your exhaust setup. That is precisely the way I am attacking it. The car is going under the knife around the 6th of September.

-m

vrus

Marcus,

Got that part.. What I am having a problem with is that people are telling me if I COMPLETELY REMOVE the first pair of cats (the ones just below the headers) that I will get a check engine light. I dont want to replace them with another set of high-flow, I just want them gone.

Kleemann is removing them because when you install the Kleeman headers, their downpipe goes in place of the first set of cats and aparently should work without problem, but, Darren just said that after he installed the K2 he got a check engine light and Cory specifically had to do some programming to eliminate the code checks.

The basic question is: Before I go and completely remove those primary cats and put a straight pipe in their place (downpipe just like Kleemanns), will I get a check engine light or will it work properly?

For reference, lets make sure we are talking about the same thing.. Below is a pic of my stock exhaust removed.. See how the first cat is sandwiched between those 2 O2 sensors.. That's what I want to completely remove and replace with a pipe. Once I do that, both sets of O2 sensors will be located BEFORE ANY CAT.

Keep in mind, Kleemann doesn't relocate those O2s as far as I know. There is a bung welded on their merge collector which is where the first O2 gets plugged into.. I assumed the secondary O2 stays plugged in where it is now.

Rafal

Good luck with your enquiry at Kleemann! Why would they help you install their competitor's headers?

Rafal

Read your statement, it makes no sense at all if you look at the exhaust system photo, or climb under your car!
There is an O2 sensor before and after the pre-cats, NOT the secondary cats. What do you mean the ECU does not give a crap about them? There are no O2 sensors anywhere near the secondary cats!

vrus

Rafal,

No one needs to help me install the headers. They are already installed. The only question I wanted answered was whether or not the primary cats can safely be removed and not get a check engine light.

It has nothing to do with what headers are on the car. I could have the stock manifolds for that matter.

If I have to hack them off and do the testing myself, so be it... I figured I would try to coroborate the rumours before going to the trouble myself.

medici78

Instead of disabling the O2 sensor why not place them behind the secondary cat?

Grumpy666

The answer to this question should be no. The second sensor it there to measure the efficiency of the catalytic reaction. The PCM expects it to see the perfect A/F ratio coming out of the cat. The first sensors sees the fast toggling of rich-to-lean in the A/F ratio, which is used to support the oxygen storage function of the converter. The PCM expects this sensor to react to this toggling accordingly. Since the second sensor sees the exhaust after the chemical reaction, it reacts more smoothly without the rapid rich-to-lean cycle. If the PCM sees the second sensor reacting like the first, it assumes the converter is failing and sets the check-engine light.