Loss of power after MODS

[SpaceGhost711]

:evil: I can't express how much of a disappointment it has been modifying my 2000 8G Galant 4G64.

List of MODS:
1. Denso Iridium Spark Plugs
2. Injen CIA positioned where the factory airbox was
3. OBX short tube header
4. Custom exhaust from header back - 2.5" pipe from the header going to a 3" Dynomax Resonator where the cat was with the O2 sensor on either side of it, then back to 2.5" all the way to a bullet style muffler with removable baffle that is 4" open woth out it, 1.5" with it installed.
5. Other MODS not related to performance:
Pioneer headunit and speakers.
Leather seats.


Fortunately the car is not loud on the inside but it sounds like crap on the outside and ir runs worse than it sound. I have lost all signs of torque, it runs rish as hell and it burns gas like a V8. I am considering buying a Apexi S-AFC but I have a strange feeling that it will not do what I want it to do. I want my torque back but I do not want to re-do my entire exhaust. I know that some will say that 2.5" is too big, some might say it's ok. Some will say I need a cat and others will say run without it. Obviously I am new to the import scene. I wanted to make this car more fun to drive but I don't even want to get on it because it sound like an airplane and performs like a pinto. I ran fine before I did anything to it. I am tempted to re-install all the stock stuff and get something else. The car only books out for like 5,000 if that. People talk about head swaps and tranny swaps and turbos before you can notice anything. I am not looking for a drag racer or drifting machine, I just want something that was more sporty than what I started out with.

What do I need? will the S-AFC trick the O2 sensors? How can I remove the speed governor? How can I make it shift harder? Should I raise the rev limiter and if so what ELSE do I have to buy? I have read a lot of forums and really have not found an answer to these questions. Any help would be much appreciated.

[theblackpearl]

hmm dude you have all the mods i have..

aem cai
obx shorty header
2.5'' exhause tubing
magnaflow hfc
magnaflow race series muffler

and i burn rich as well but i havent lost any torque..i kept up with a v6 g off the line..i dont know what to tell you man..my car sounds crazy as fuck but it doesnt perform shitty like you are talking..im confused something isnt right..

[gottmanMR]

First off, if you haven't reset the ECU, then you need to get this done by dissconnecting the negative battery terminal for a few minutes then reconnect and drive for awhile. If you have an A/T then get a high stall torque converter, it will help compensate for the loss torque because of lost vacuum pressure due to the larger 2.5" exhuast piping. There are several ways to resolve the running rich problem, you can install some kind of ignition amp like an MSD to burn all the unburned fuel or tune with an S-AFC. Lastly for your horrible sounding exhuast, can be resolved by getting it dyno tuned and your car should sound and run better, and perhaps regain its gas mileage.

[Hodgson316]

something is definetlly wrong w/ your g... get that shit checked out before you get rid of it like that... also look into some nitrous

[cardude03]

all great things, but about the resetting of the ECU, i dont know if anyone is really sure about how much time it really needs, i've heard 10 minutes, i've heard a couple hours. the best thing for you to do, as i have learned in the past, is to just disconnect the battery at night, leave it like that overnight, and then connect it back when you wake up the next morning, then it should have DEFINATELY reset by then. and i have also heard stories about driving it hard right after you reset it, to map out the ECU more aggressively, im not sure if its true, but maybe you might want to keep that in mind.

[theblackpearl]

yeah nitrous helps too..lol

[krispy03]

S-AFC II GET IT!!!
with your mods you wont regret it. also get a walbro 190 fuel pump.
i installet the afc the otherday and its awesome. i leaned out my fuel and im getting way better gas millage, and my car pulls like a mother fucker.
as a matter of fact i whopped on a V6 grand prix on the way home from work. and i got a 4 banger

[theblackpearl]

really? the safc-II helps that much?

[neel9]

sorry but what is the safc?

[g-ridda]

to me your exhaust seems a lil bit to busy with all the size changing im not sure if it matters but if u think about it you can imagine how the air would flow through the exhaust and it also matters who welded it on and if it was mandrel bent u shold look into those things. also a shitty cheap muffler can make it sound dumb too ask around and find out wut sounds good. 2.5 isnt to big 3.0 is tho

[peanotation]

first, reset your ecu.

second, <span style='font-size:25pt;line-height:100%'>DO NOT</span> buy a s-afc. that is for TUNING, not for fixing problems with your car. you have to be running healthy and correctly or else you're going to make things worse. all you guys telling him to get an afc are just gonna make everything worse for him.

[SpaceGhost711]

Wow, I appreciate everones input.

First off:
I am sorry I should have mentioned this before but I read in one forum that to reset the ECU you have to leave the negitave terminal disconnected for 30 minutes, let it idle for 15 minutes and then turn it off and start it up again and that's it. I don't know where ppl come up with this stuff and whio knows really how to reset it. I will try leaving it unplugged overnight. This will probably mess up my keyless entry thing so I will have to read the forum again and how to reprogram it.

Second:
I do agree that my exhaust system is a little busy. I went with a bigger resenator becasue I wanted a deeper tone but the crappy muffler I have has to go. Should I get like a 3 chamber flowmaster or dynomax muffler for V8s?

Third:
Has anyone sent thier chip off the Jet to have it reflashed? I want to cut the speed limiter and make it shift harder. From what I read, I would not benifit from raising the rev limiter. What other options are thier for us?

Fourth:
N2O! How much does the typical kit cost?

Thanks again for all the input. I guess i'll keep 'er

[pinoyesv6]

are you pulling any codes? you removed the cat and replaced it with a resonator. if you are pulling a code then your car might just be in limp mode from not finding the cats.

[SpaceGhost711]

Have not checked for codes but my check engine light is not on. I was told that it normally take about 100 miles for the ECU to quit trying to compensate and post a code but I guess it wouldn't hurt to check.

[SpaceGhost711]

another thing, when the guy was installinh my exhaust, I believe he did an ok job on the welds buy I don't know how the pipes are bent. He put them on a machine that crushed them into angles.

[g-ridda]

for your sound i think u might want to try a borla muffler mines is plenty deep i got it from meinike muffler shop and i still have my stock exhaust if i had a 2.5 i would prolly create a monster try borla or flowmaster but just the muffler rememeber u dont have a v8 so i wouldnt try putting those type of exhausts on your car unless u are gettin forced induction but im not really sure can anyone back me up on that? you should really do somthin about that resonater.

[qnz]

i4s dont have a speed limiter on them.... im pretty sure

[galant03-4g64t]

i just got one of the exhausts off ebay....... works fine, and sounds great...... did you gap your plugs right????? and you need to put a cat back on there

[SkylineG1]

all great things, but about the resetting of the ECU, i dont know if anyone is really sure about how much time it really needs, i've heard 10 minutes, i've heard a couple hours. the best thing for you to do, as i have learned in the past, is to just disconnect the battery at night, leave it like that overnight, and then connect it back when you wake up the next morning, then it should have DEFINATELY reset by then. and i have also heard stories about driving it hard right after you reset it, to map out the ECU more aggressively, im not sure if its true, but maybe you might want to keep that in mind.

When I went to the dealership the mechanic who has an EVO said that you should disconnect it for 45 min- 1 hour. Then drive the piss out of it!!!!

[SpaceGhost711]

Well... after about 100 miles, my service engine soon light came on (expected that). I guess a good indicator that my ECU was reset is if that light goes off. I will try just leaving it unplugged overnight. According to a service manual, the heated O2 sensors should read 0-400mV(front) and 600-1000mV(back) at idle. Are there any O2 sensors available for us so that it is sending the right voltage? I really don't want to put a cat back on until I have to.

Ok lets talk about vacuum and timing. Is thier anything on the market to boost vacuum presure? If I advance the timing, would that help? I did not gap the plugs, they were pre-gapped and I don't have a tool to do it.

Thanks for all the info