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Hello everyone, I have a bit of a complex issue with my Z, this week I took it to a shop in northern okc and had it run on the dyno. The fellow there told me right off the bat that his dyno read low, but he was only charging $60 for three pulls and A/F ratio hookup so I did it anyway. The first pull was pretty miserable with 236hp 223ftlbs of torque, after putting the fan in front of the car, it pulled 244hp 228 torque. The third pull made 245hp 230 torque. These numbers told me that the Z needs a tune, and I’m leaning towards UpRev as far as that goes. The mods include K&N short ram intake( the fipk model) plenum spacer(5/16in.) megan racing longtube headers and true dual replica exhaust and UR underdrive pulleys. I will say that I’m new to cars and tuning but I know enough to know that running lean poses a threat to your engine. So the thing that bothered me the most was the A/F ratio; it seems to be sitting in the 14s at Wide Open Throttle. At that time I immediately starting thinking of ways to fix the problem, but a couple of days ago it occurred to me that I should find out what is causing it first. I’ve come up with three major possibilities: The mods without a tune. The CEL code( I’ll explain this in a moment) and the intake. I didn’t choose any of the mods related to the engine/powertrain, that was done by the previous owner who is seemingly impossible to find and talk to. (the car came from a dealer)
Here are the second and third dyno graphs.
On the way home from the shop the CEL came on, so I checked it and the code was P1273 after looking it up these seem to be the causes for the light:
- Faulty Air fuel ratio (A/F) sensor 1 Bank 1
- Faulty Air fuel ratio (A/F) sensor 1 heater Bank 1
- Fuel pressure
- Faulty Fuel injector
- Intake air leaks
- Faulty Air Flow Meter
I just cleaned and re-oiled the filter a week or so ago, and it looked to me like there was a velocity stack built in to it. Another thing that came up was this; I’m really new to this and this was my first time oiling a wet type air filter, so is there a possibility that to much oil could lead to a light coat of oil being sucked into the intake and coating the MAF causing bad readings=bad A/F ratio? I’ve only ever heard of this on FI cars (i.e. STI, Evo, etc.)
I have searched and cannot seem to find anything that will help, although I found a thread here on the forum that lined up with what a buddy of mine said about the longtubes throwing it off, and the thread was regarding test pipes. I’m planning to get it tuned, but I’m leaving for basic training next month and I’m having to stay local, so with nobody local who can do UpRev tuning it’ll have to wait until afterwards. There just isn’t the time for the etunes right now, but what I can do is find the source of the issue and keep an eye on the A/F ratio with an Informeter or gauge. I’m sure that the answer to the problem is right there in front of me, but I think it’s possible that any one or more of these issues could be working in conjunction with another to cause the lean AFR. Any help is much appreciated and thanks for reading.
Just get osiris standard...ur code is going to continue to be there unless you get it tuned or you could add non foulers but that doesn't really help you from running lean just won't get a cel....and yes your filter could be over oiled and you might have some on your maf I run a dry amsoil filter....I believe 1273 and 1283 are for your bank 1 and 2 sensor 1 sensors which is the primary sensors on the headers secondary are for the emissions and those are the ones that adding non foulers sometimes prevents a cel
Last edited by johndoesdamage; 11-22-2014 at 02:05 PM.
11-22-2014, 08:41 AM
Bolt-ons without tune + CEL and its running lean.
