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Car failed smog today. Freakin CA smog, man... as you can see, it was fine at 25mph (co%) was right at max but the NO and HC were super low. So would my initial assumption be a bad cat? Though cats don't affect CO from my understanding so maybe my o2 sensor is going too? But if it was, wouldn't that CO show up on the 25mph test too?
Or am I looking at this the wrong way? The HCs are awful high.. perhaps a misfiring condition causing improper combustion?
Also it's a jdm h22a, my aem cai has the part number for only the h23 and f22, not the h22. Yet the state of ca air resource board has no part number listed for the h22 unless it's an h22a4. So I'm not even sure what I'd have to do except get a stock intake to put back on.
Well backinblue92 I have an Injen short ram intake with the carb legal sticker on it that I use when I need to smog my prelude. I use it instead of my Fujita intake that has no sticker on it. Shockingly I passed my last smog test with my 2 year old Magnaflow California converter but barely and I got my car super hot before I took it in for the test. California is so full of tree huggers its insane and it makes it harder and tougher for guys like us to pass a smog test. I know for a fact that a damn intake would never make you fail the smog test its just another bullshit item that the state can have restrictions and control over. How old is your cat converter and your upstream O2 sensor on your prelude?
Well I got the intake thing figured out. Had my car passed everything else I still would have failed on the intake though. Apparently the CA air resource board (carb) changed all the numbers on executive orders.. long story short, called AEM and they gave me a new carb number that my smog guy said would be fine after he looked it up, however, at some point I do have to take a pic of my Vin and intake and fill out a pdf file for AEM to get the actual sticker. Load of bullshit. All the 4th gen intakes are the same!
I had a shop quote me $275 installed for a magnaflow cat, however it will be universal and be welded in unless I go with a far more expensive bolt on. It's a hard bolt on cat for me to find a deal on cuz it's gotta be obd2 but for 96 only; the 97+ part number is different. If I go the universal route, it's 2" stock exhaust diameter? I was gonna try to source the cat myself
And yeah it's the original cat, so I guess after 19 years it's finally done the downstream o2 isn't throwing a code but I think the pre-cat o2 is throwing off my air fuel mix. It was running at 14.1, which as I understand is .7 off. Unless I've got an egr problem, which perhaps I should clean that while I'm at it. Idk. Apparently 1996 obd2 isn't what 2000+ obd2 is; in that it was the first year and something being off won't always throw a code. They were still working out the bugs at that time. Apparently.
I see where you are getting super frustrated as the part numbers for your 96 obd2 Prelude are not the same or shared with the 97-01 Prelude California converters. Honestly you have two options get the universal converter yourself or from the shop and have them install it as the welded in unit. Or you can get the shop to cut off your old converters flanges and have them welded to the universal cat making it a bolt-on application. Second thing would be to purchase a direct fit or bolt-on California converter from Magnaflow for a 97-01 Prelude and go get it smogged with that on there. Your smog shop shouldn't even be looking at part numbers and all that **** on the converter or at least mine never did so you must be going to some cut throat people who are way "by the book." Good-luck with it and yeah after 19 years I would change the cat and the front o2 sensor it could only make the smog go smoother for you, think of it as money well spent.
I never think of anything smog related as money well spent, lol. For one 49 other states don't give a crap, and two for a car that drives 3k miles a year, I pollute less as is than one smog exempt 18 wheeler downshifting on a grade or one freaking school bus. Lol
Good idea on having the universal cat flanges bolted on. I don't like the prospect of all that being welded direct to my car. I had thought of ur idea for using a 97+ cat already. It's not about the smog guy checking my cat #, he didn't this past time (I actually considered a 49 state cat inside the oem heat shield but decided it wasn't worth the risk if the CA cats were built differently) but it's more about fitment concerns. The part number on my 96 cat starts p13 and the 97+ p5m. So I was thinking that perhaps there would be fitment issues with the downstream o2. That, and 92-96 and 97-01 don't always share the same exhaust systems so there could be potential fitment length issues. Potentially. Idk
Edit: I meant fitment length issues with a bolted on cat. It may be moot point anyhow. For $275 installed I may not find much of a better deal in CA unless u have a good deal or know a place online.
Well I do have my 1998 Prelude with a Magnaflow 50 state legal California cat and I ended up purchasing a 49 state legal Magnaflow bolt-on cat as well. The company I bought it from was on eBay and I ended up telling them that it was for use on my track car instead of my Prelude of course I was lying though. I can take measurements of my cat and give them to you so you can compare them with your 96 Prelude converter if you would like. I think you should just try and buy a 49 state legal cat for the 97-01 prelude so you can save money and have it be abkle to bolt-on.
Could u measure it if you have time? That'd be awesome. All I need is the length, as I'd assume the exhaust diameter is the same 2". I'd have to check. I'd go the 49 state route if it's a 3 flange per side bolt on. I highly doubt they'd check, though knowing I needed a cat they could check. Maybe go to a different shop...but they didn't last time. No shop will install a 49 state cat so yeah it's have to bolt on myself.
What'd u do with ur 50 state cat, just keep it in case u get busted? The price difference is enormous, and I do wonder if they are built differently than CA cats. U used it for smog? No company will ship a 49 state to CA so I'd have to search around ebay.
Also I suppose I could skirt it by having Kragen order a 50 state magnaflow cat and memorizing the carb # off it then showing up at the smog place, if they ask, saying oh yeah here's the carb # because I reused my oem heat shield (is the heat shield welded on? My oem one looks to be bolted on but that may be a secondary measure). Haha
Edit: just got all the part and carb # for magnaflow off Californias own database. They even let u print out the carb stickers lololol. Idiots. I suppose now I could bolt on a 97+ 50 state if u measure and it fits, if not, a '96 49 state with 50 state papers. And to be sure, casually ask if it'll pass visual before he starts the actual test.
Last edited by backinblue92; 07-09-2015 at 07:30 PM.
Okay well the length of this 50 state cat and the 49 state at are the same, they come in right at 13 5/8 inches from flange to flange. I have pictures of it below so you can take a good look at it. I kept the 50 state cat in case I don't pass smog with the 49 state cat but honestly they look identical in the way they are made unless the precious metal inside them is different but doubtful in my mind. Also the Magnaflow cat part number should be 22644 and you just have to find some seller on eBay to sell you one. They are not to expensive I believe I paid $150 for mine.
Bingo. That's perfect. Same size as mine but I'll double check. Thanks for taking the time to measure it and post pics man. Direct fit for $150. Yay.
I also found a way around smogging in the future. My godfather owns a house in Tuolumne County aka Yosemite/Tahoe and those counties do not require smog except for change of ownership. So after I get this smog completed I'm going to change the cars garaged/registered address and my personal DMV home address to his house in Tahoe, then wait 6 months and then change my address back to my actual real current addy, while leaving the cars registered addy in Tahoe. And once a year I'll drive 4 hours up there with the family, take a little vacation and stop by the DMV to pay the fee. Lol
I guess people try to do what I'm doing but with PO boxes and it doesn't work like that u need a real physical address so it should work. I'd honestly try to do this right now but given the state knows I just failed smog already, it would look fishy and I don't need any trouble. So I'll take care of my issue this time, then do it 6 months from now.
Ended up getting a 5th gen magnaflow 50 state cat for $120, a friends uncle cut the old cat before each flange and welded the new one in for free as part of a trade for some spare parts. So it's still bolt-on. Yay.
Then I did a compression test and forgot it would throw a code so I'll have to wait to smog now til it's gone through a drive cycle. Or ask the shop to do a scan beforehand. Sigh. Lol
Thanks again for the measurements thirsk! U saved me a cool $100 easy
You are welcome I am always here to help. I wish you the best of luck on passing smog which I am sure you will now with a fresh cat on there. That is awesome you scored it for $120 and had it welded on there with the flanges still there, makes it a thousands times easier if you ever have to remove it.
I'll prolly remove it when I'm done with smog and put in a test pipe. Lol. Save the good working cat for the next smog! Maybe. My fiance is a police officer. So maybe not. Lol. She knows about my jdm h22a not being bar'd but told me to keep anything else illegal I do to the car to myself. Hehe
Oh, and I actually failed smog again with new o2 and cat. Yay /puke
Basically, what I'm dealing with is a rich condition at low speed that is causing my HC and NO to stay elevated. That NO is my indicator. But... my idle is perfect. There's no vacuum leaks. My pcv is working. My coolant is proper temp and thermostat works. I get 25-27mpg city and highway combined. I'm out of ideas. Was gonna borrow an obd2 scanner to check my fuel mix but I bought a "guaranteed to pass" bottle as a last resort.
So how can I kill this rich condition? The Google is failing me because my issue is so specific and nobody ever posts the solution.
What that is not right at all you should have passed the smog no problems at all. Did you drive for a little while before you got is smogged? I remember when I first put on my new cat the smog tech told me to drive it for at least 20 minutes because it was a brand new cat and needed to be broken in and get super hot to do its job.
Yep, I did. About an hour night before, took it in to smog after another 30min of 5-6k shifts (to hell with the new clutch lol) then 20min freeway cruise then to the shop, idled for 15min before it went in, FAIL. So annoyed.
And out of ideas. How can I lower these HCs? I give up on fixing the real issue, if it's only present under acceleration I could care less. Is guaranteed to pass or seafoam my friend now? PS the smog guy is turning into a dick. He said he won't get me in quickly if I heat the cat again cuz he will refuse to smog it if the cat is already superheated.
What the hell kind of smog guy is that what a *****, cats work at their optimal performance when they are super hot what an idiot. Well have you ever adjusted your ignition timing via the distributor? Have you changed anything on your distributor lately? I would try the guaranteed to pass stuff you should be able to pass this time around.
The sad thing this smog guy he is actually very knowledgeable. Then he went on this long rant about how the state is watching his every move, basically you know the type. Easily scared by the big bad government. Yet he says nothing when he looks up what an H22a is. So who knows.
Anyway. OBD2 doesn't allow for ignition timing. Or I'd already have set it back 15 degrees lol. Um, yeah rotor cap wires and plugs. Didn't do the coil pack but my plugs show no indication of anything going wrong. They are just the right color.
I was thinking maybe an ounce of pure acetone mixed with a half tank of gas, that runs clean but it could wipe out my sensors and cat in the process. Might just go with GTP. I already bought it. Just working up the courage to put it in my tank. Lol. I'm no god-fearing man, but anything other than actual top notch gas in my tank scares me.
It's true though smog techs and shops are under the microscope and will be for a long time. He has good reason to be crazy about his license since if he ever does a bunk smog and gets caught he loses his license and could serve some jail time. They need to make the smog requirements less strict in California they are hard enough to pass and to buy a California cat is just to much money. I am thinking just pour that GTP bottle in your tank follow the instructions and go pass this damn smog test you have been through enoough with this mess and I am thinking you will pass this time around I don't see why you wouldn't all your sensors and vacuum lines are hooked up properly and your emission items are all there so there's no reason to not pass.
Alright so I have some update. I took half the day off work to get this settled. I took it by a shop that does smog but also specializes in older model cars on a recommendation from a trusted friend. The guy had some gleaming RX7s out there, straight Dominic Toretto style. Lol. Anyways. So he pulled each plug wire out one at a time, grounded to the inner wall, and the engine ran a little rougher but idle stayed at 750 across all 4 cylinders. He said that indicated that all my idle, IACV, FITV, EGR, etc was working properly. Which would make sense to me.
Now my WOT compression test, which read 250 250 205 250, and the low cylinder didn't change with a little oil, means my rings are good and its a valve issue.
Throw the two together, and you have a valve(s), most likely the low cylinder, that is creating a misfiring condition, making high HCs and causing a rich mix at idle. Which would explain my higher-than-it-should-be .37 CO at idle as well. The higher NOx could be carbon deposits, and while it passed, is something I will address with seafoam after this damn test is done.
The o2% is still holding steady at 0.0, so the cat is taking all the air and doing all it can.
I'm thinking I will do a valve adjustment, as it won't take long, and save the GTP as a last-ditch resort. Everything I believe here sounds fine and dandy to me. Does this make sense to anyone else? LOL
Makes sense to me that low compression in your one cylinder is something that should be addressed after you pass smog. I think a valve adjustment could help with the issue but for a long term fix pulling the head and doing a valve job with new guides, seals and of course valves would be great. Keep us updated on if you pass smog.
Will do. There's enough threads floating around without resolutions as it is lol. I only need this smog anyways. I'll rebuild the engine by the next smog or just register it at my godfathers house in smog free Tuolumne county. Lol
Do both rebuild it make it perfect and then register it at your grandfathers house so you do not have to deal with this BS again. I know a lot if not all the other 49 states just have to pass inspection and your good to go California needs to adopt this philosophy. I swear we get the worst end of this smog crap.
Good morning! Yes I agree the smog is outta control in CA. I love my "old" car. I have a newer daily but I'll never literally never sell this one. So I need a long term smog fix lol.
I did a valve adjustment last night. Intake valves were all topping out around .009 and exhaust had +/- .003 tight and loose valves. So it's all within spec now almost. I couldn't finish the final #4 cyl intake bank because I had to put the kids to bed (and myself haha). Also, because my only deep 10mm I was using for my nut locking tool fell into a crack in the cowl and behind the windshield wiper module. So that's gone lol
Do u know if there is a vacuum line I can pinch to apply vacuum to my egr valve to ensure it is working 100% properly? My IM doesnt have plugs or visible welds so I'm not gonna attempt to drill it to clean the actual egr ports at this time. That's pretty much the last thing on my list before I seafoam. Then oil change, then back to pass smog.
I'm honestly learning so much through this smog debacle about the car, and I was talking to my fiance last night and she was saying that my new approach should be "it'll be alright, cars are fun for u, you're talented and will solve this." She's right. I'm done wasting frustration on it, yknow? When something needs to be done, I do my homework and do it. So I'm just gonna woosah on all this. S'all good. World isn't ending.
Got clients stacked up til 2. Then finish all the work tonight and smog this lady monday! Hahaha.
Good luck, sounds like you are following all the right steps, and it is just being a bear!
Colorado is still very strict as well, at least in the major cities, with the dyno emissions testing. I have had numerous problems with the height of my car on the dyno, what wheels I had on etc, even before testing my car.
Luckily once they finally accept the car and test it, it has always "fast passed" the test, even with the JDM engine and vafc, but I do use a bolt-in stock Honda cat.
The last few years I have been exempt from testing as the car was out of the country, but whenever I go back it will be a different story. No more egr, iacv, fitv, etc. along with the ported out intake, 1000 cc injectors, Hondata, and all as well.
Thanks man! I'm trying to follow the right steps, fix the issue, yada yada. I'm very serene about this now. But the other half of me still wants to strangle someone. Ha!
Yeah, I can't speak for Denver but you're in for a little bit of a rude awakening. I'm sure you've kept tabs on it but still a 30% CA fail rate according to a tech I spoke with is no small number. No idea what your mods will mean for your area, but I can tell you you'd fail CA visual before you even started lol.
Oh, that gives me an idea. Pump the air in my tires waaaay up. Like 40psi easy.
I've decided against Seafoam. I'm worried about its potential effect on my new cat, that, and I just don't like the idea of anything but gas in the car. That may change if I fail again. Lol
07-07-2015, 02:33 PM
smog questions
the downstream o2 isn't throwing a code but I think the pre-cat o2 is throwing off my air fuel mix. It was running at 14.1, which as I understand is .7 off. Unless I've got an egr problem, which perhaps I should clean that while I'm at it. Idk. Apparently 1996 obd2 isn't what 2000+ obd2 is; in that it was the first year and something being off won't always throw a code. They were still working out the bugs at that time. Apparently.
