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The Berks arent carb legal either afaik. Aren't they only 49 state legal?
Also Balanbro, the second o2 sensor does nothing but check for cat deficiencies. I for one, have found a different fix to this problem....I think I'm going with race pipes. |
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No high-flow cats for these applications are CARB legal.. and while they will pass the sniffer test.. it's against federal law to replace your factory cats for use on the road. HFCs are sold with the intention that they will not be used on federal roads.
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also wanted to mention that i just received your catback system and love it! I am definitely going to be getting your headers and g3 intake as well. great products |
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yeah maybe compliant is the wrong word, maybe friendly, it was something i read on a post from kyle at importpartspro.....haha...thats what i was trying to say, maybe i just read it wrong. as little as i do know about this stuff i understand that its a diagnostic system.
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EDIT: I should clarify.. secondary fuel trims associated with CELs.. |
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This is an interesting thread, hopefully people take a look at it before plunging into purchasing HFCs. There is a little more to it with this car than I have experienced in my previous vehicles.
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Here's my take on things.
If your gonna get a CEL with HFC's, whether it be after 200 miles or 3k miles, might as well just get test pipes and maximize power output. It wouldn't make any sense considering the price of HFC's, unless you live in a highly regulated state like CA. As someone previously stated, these things just come with the territory of modding. The light never bothered me but I guess I'm just so used to it that I never notice it anymore. |
I've done a lot of modding, including forced induction and I've never tolerated the light. But I do agree you may as well just get the test pipes anyway.
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the test pipes only have a rasp for a slight moment (2600-2900rpm) under medium acceleration. but i loveeeeeeeeeeeeee the sound of them. super aggressive and almost like an exotic at the higher rpms. am i the only one with test pipes on the 370 here? as for my service engine light, i will try that ss wool this weekend maybe. if that doesnt work i will do the other fix when i have time (probably a couple of weeks). the light hardly bothers me anymore. the sound and performance of the pipes far outweighs the annoyance of the light.
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I want to see numbers -- numbers are more meaningful than sound to me. |
the dyno that i will go to is a mustang dyno, so maybe we can compare my run with RCZs baseline (yes diff dyno/diff day). i will update that thread once i do it
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Test Pipes will cause the light to come on and there will be not much you can do to not prevent the light coming on with those. With HFCs though you have a chance of preventing it with the methods above. Also less rasp, less smell with HFCs.
Not sure why Stillen (maybe due to lack of experience as they don't specialize in ecu tuning) keeps saying the o2's behind the cats that do the fuel adjustments when it's the front o2's that do the fuel/air adjustments as they need a reading before they hit the cats. UPREV has already disabled these o2s on several cars with no issues. |
nice. we got a guy on the inside. haha. so how do u propose to fix the code that the computer is spitting Jesse? uprev?
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^^ you definitely have more knowledge than i do. I completely agree that only the first 02 have an effect of fuel. i think NismoZ brought that point up too
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I think some of your guys are misinterpreting Stillen, this is why he edited to add that they specifically affect CEL. The rear only checks for cat deficiency. The fronts control fuel under load, aka when it matters. You can drive the car with the rear o2 sensors completely unplugged and it wont affect anything. Its the CEL's that you have to worry about if you don't like lights on the dash like me.
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With my 2005 STi, I just zip tied the rear o2 sensor under the car, so it was never screwed into the exhaust. I never had an issue.
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In theory if the secondary O2 sensor always sends a lower voltage than the front then the resistor trick could work. However in reality it could get a little more complicated than that as I'm not sure that the voltage response of the O2 sensor is linear.
The dummy sensors are similar, however they always send back a fixed voltage according to what the ideal is supposed to be. |
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ETA: Making custom O2 simulators |
I'm still wondering one thing, doesn't each bank have 2 cats (4 total for both banks?) The typical OBDII arangement was:
O2/AFR-->1st cat(usually in OEM manifold)--> 2nd O2/AFR-->2nd (downstream) cat I was under the impression that the HFC replaces only the downstream cat (after the last sensor). So how would the sensor know whats going on further downstream? It should only be monitoring the upstream catalyst efficiency in theory. Please tell me if I'm wrong here because I'm assuming this based on the late 90's OBDII cars I am familiar with. |
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Our car only has 1 cat per bank. The arrangement on our car is Exhaust Manifold -> Cat -> (rest of exhaust), and there's an O2/AFR sensor in the exhaust manifold, and another O2 sensor right after the cat. The one in the manifold is the expensive wideband one that the ECU uses to regulate AFR. The simpler O2 after the cat is just used to validate that the Cat is functioning properly. |
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I've had both(pipes and HFC's) on various cars and I've always thrown a CEL....every last time. If it doesn't happen with the 370Z than that's a great thing, but I think it's way too early to even make it seem like a code will not be thrown. |
Hello everyone,
I'm new to this forum.. ill be getting my 370z in june. Im thinking about getting the Berk HFC's. where can i buy this 02 simulator thing or whatever? What exactly does it do?? Im kinda a noob so go easy on me :P (thinkin about gettin the stillen headers, exhaust, and CAI; berk hfc, and hotchki sway bars- lemme know what u guys think of that setup) Any information of this 02 thing is appreciated lol, Thanks, Grant |
The ECU will only look at the secondary O2 sensor during closed loop operation (i.e. lean burn, steady freeway cruise, idle, etc). The ECU will make small adjustments to the fuel trims based on the small adjustments made during closed loop operation. This is on the order of a few percentage points. I don't recall ever seeing anything over +/-5% in the last couple of years.
If you guys have ever called Berk for tech support you've heard us say, "Clear the ECU learned values before running the HFC's. You will run less of a chance of throwing a CEL light". Over time your ECU may have adjusted based on your driving habits. By clearing the fuel trims you give your ECU a chance to start back at zero and readjust to the new cats. The cat is in essence an oxygen storage device. When installing a BERK HFC that flows twice as much as the OEM cat it does not have enough contact time with the catalyst to "scrub" the exhaust gas and let the reaction occur. So the O2 readings will be different. Most of the time the thresholds of CEL or no CEL are large enough that the ECU will readapt and the CEL will stay off. However some of you who were already operating on the outer range will pass that threshold after a few drive cycles and illuminate the CEL light. During driving situations where the engine sees load it will completely ignore the secondary O2 sensor and go off of it's pre-programs maps. On one of our race cars we actually did not use any O2 sensors at all! We would run completely off the pre-programed maps on the stand alone. We would make small tweaks to the maps for high altitude race tracks and summer/winter weather. So, the moral of the story..... the secondary O2 sensors technically DO make tiny fuel adjustments in concert with the primary wide band sensor in the header, but only to make the car run as clean and lean as possible during steady cruise. From the stand point of the car enthusiast, they don't do squat! :) And to set the record straight in plain black and white: Berk HFC's are not SMOG legal in CA. Can they pass a sniffer test? Yes, all the time. But Berk Technology does not guarantee emmisions performance. The vast majority of you will never thorw a CEL. However there is a very small percentage of you who will throw the occasional P0420/P0430 CEL. Down the road there will also be a very small percentage of you who throw those CEL codes with the OEM cats! Hope that gives you some good info to chew on! Cheers guys! Berk Technology |
excellent Berk. thanks for that post.
Now can you please get some pipes in stock ? ;) |
^^ya berk. he's even tryna buy mine off of me!
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Actually Jesse, Berk is dead on when it comes to the function of the secondary O2 sensors based upon my conversation with my R&D guys today on a different application that rolled into this discussion.
My understanding (and I'm in marketing, but privy to a lot of the tech going on) in regards to these sensors (including their function on previous Z's and the G35/G37s) is their drivability control, the secondary fuel trim function, when you're not under hard throttle situations where pre-loaded maps take function. Idle, cruising, CELs can be affected. I'm not going to comment on your knowledge, obviously I would have no idea, but in regards to this car, engine, and applications, I wouldn't be so quick to discredit some of the people posting on this forum.. |
Actually one section of your post you are wrong.
Nissan ECU's do adjust for the type of driving you do. If you drove like a granny for a long time, then wanted to use the power out of your car for a road course or something your car would not feel like it has the power as it once did. I have seen this on many Nissans. Once you drive it aggressive after a while, it learns your driving again and makes the adjustments. Quote:
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X2, but still the 2nd O2s on these cars do not make adjustments to the Fuel trims period. Ask Technosquare or UPREV and they will tell you the same. |
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