Bogging After new Exhaust?

[ekR]

Hey guys,

tl;ldr at bottom sorry for the long story I just don't wanna miss anything

Got my car back yesterday a new custom exhaust system was put on it, upgraded from the stock one I was running with my b18c on aftermarket headers.

Shortly after I went to a friend's house who installed a cold air intake - noticed that when I got the exhaust done there was a bit of back fire happening as I drove out, mainly when I was shifting gears (not loud or anything but just small pops coming off the tip, so didn't seem like a cause for concern).

While I was driving to my friend's house for the intake I noticed it was really difficult to get on vtec or just rev it up in general, it's almost like as soon as it got to vtec engagement the car would start back firing a little bit, hesitate, then run fine and pretty much rinse and repeat every traffic light until I get there.

I got the cold air done, and as I drove off the car basically went limp (this was on an uphill) battery pretty much seemed like it died or there was no power to ignition or something like that and I pulled over, waited a moment, turned it back on - this was ok, tried to move again, same thing revved up and then almost like there was no power it just turned off.

My friend came out to have a look, we ended up moving it to flatter ground (wasn't going up a steep hill but it was an up hill road), turned it back on friend told me to do some rounds around the block and see if I could get on vtec and see if the back firing was just due to excess fuel that needed to be burned off... hit vtec for a few rounds around the block came back felt 100% better to drive thought there would be no more issues.

Had the occasional back fire here and there on the way home, but then it started bogging, basically 2-4k revs occasionally it will hit it up, maybe hesitate back fire a little but then almost change it's mind like nah this is cool let's keep going. Accelerating out of first and second into vtec is pretty much out of the question it will bog if I try to, but 3rd, 4th and 5th gears are ok to drive in.

If I drive normally which I do 95% of the time there is 0 problem it will run like it should.

Car seemed to be ok on the stock exhaust, really problem started after the exhaust, brand new cat and full 2.5" exhaust was installed all the way through from headers to tip so not sure where the issue could be.

I was suggested may the car needed a tune to fix up the fuel/air ratios with the cold air and exhaust but I'm running a factory jdm type r ecu that isn't chipped so tuning it isn't an option for now.



I'm not very savvy when it comes to stuff under the hood, unfortunately I haven't done much to check what's going on but so far I have tried to change the battery with a brand new on from super cheap and have checked the oil on a cold start, dip stick is registering just under the 2nd dot like it shuld.

Car is driven very sensibly, barely ever speed due to the old exhaust I thought getting on it too much might damage something since there wasn't as much flow and it was the stock ek1 one from factory, I was planning on actually using the car for it's potential after the exhaust but unfortunately I can't at the moment.

Where would you guys start?

Check Engine light is on, I tried to do the paperclip trick from the ecu but not sure which connector it's supposed to go in as I can't find the blue one like all the videos describe. I will definitely take it to a mechanic but just wanted to know what I might be able to do in the mean time

tl;dr - Car's exhaust was changed with a complete stock 2.5" all the way through exhaust yesterday, installed a cold air. Car seems to bog between 2-4k rpms and very hesitant getting on vtec, backfires a little not sure what the problem is, have checked oil and replaced battery issue still existing.

Things I could try in the mean time?
Injector Cleaner? Does this sound like the engine isn't getting fuel?
Fuel Filter? not sure when it was last changed I would have to assume when the new engine was dropped in but I'm not 100%


pls halp

[Daveho1]

Pull the code.
Passenger side under the dash near the door, it's there somewhere.
Let us know what code you get.

[amant02]

Why the fk would you drive your car with a check engine light.

Why the fk would try to engage VTEC with a check engine light.


My money is on O2 sensor rooted.

[Daveho1]

A lot of people do it mate, Donno why but they do, no point guessing what the issue is as the answer is stored in the ECU..
Point is don't go replacing random shit, people's random musings on what might be wrong are irellevent, the car can tell u what's wrong so;

Pull the code
Diagnose the fault
Confirm the diagnosis
Repair as required.

[ekR]

Why the fk would you drive your car with a check engine light.


Why the fk would try to engage VTEC with a check engine light.


My money is on O2 sensor rooted.

The car was recently converted the guy who did it told me it was an o2 sensor and that he had ordered some to come in but they would take a while to come in told me it was ok to drive atill though and its my only means of getting to work so yeah unfortunately i have been on his guidance i know its not ideal but yeah fml

[ekR]

Edit: I found the connector that you're supposedly supposed to paper clip but it's not connected to anything?

Is this normal or have I got the wrong connector?

[curtis265]

Your O2 sensor is shagged. The shop fcuked it up or fcuked it off.

99.99% sure

The popping is normal. It's only been amplified by the new exhaust.

[connorling]

happened to me before , it was caused by the exhaust guy left something in the exhaust and restricted the flow, couldn't get any codes and I was pulling my hairs out, mechanic took the exhaust out and something was stuck in it.

could be simply thing like that or O2 sensor not plug in properly?

[ekR]

the o2 sensor is a known issue, apaprently it was on it's way out when the engine was installed - either that or maybe the one connected to the old d16 was reused? Is there a specific b18c one you should be using?

Long story short I went to a few mechanics for other work all of which identified either the o2 sensor wasn't plugged in (and they then plugged it in) - when I left the exhaust shop the guy again said the o2 sensor was plugged in because it wasn't so it looks like it either keeps falling out or maybe it's not the correct one?

I don't think a new o2 sensor was put in when I got the b18c so could it likely be the issue?

Really appreciate the feedback btw guys, love my car and it really has got me on edge lol

[ekR]

Hypothetically if it is an o2 sensor showing on the engine light, would it fix the bogging?

Could it be a simple tuning issue?

Like I said we went from a stock exhaust (1 and 1/4 inch?) to a 2.5 inch and a cold air intake

Could the air/fuel ratios just be wrong?

Will go and try and get the engine codes again in 5 minutes just getting ready to go to work

[connorling]

exhaust wont alter the AFR that much to cause you drama
I put in 2.5 inch exhaust, header and intake on my b18c before no issue

[ekR]

did you install a new header too ? Where did they mount the o2 sensor ?
Understand you have installed an exhaust possibly TWICE the size needed for your engine. You have essentially lost power from low to mid range - I would bet the issue lies in your "feeling" of the car right now compared to stock. With your new setup the car will actually be slower in all situations

To the guy who posted this and deleted his post (not sure why) gonna answer the question anyway for everyone else.

Yes, the b18c was installed with after market headers. No the issue doesn't lie in the feeling it genuinely does not "feel" like it should be running the way it should (i.e shouldn't be bogging at least).

I don't believe the exhaust is too big, a stock dc2r comes with a 2 inch exhaust so 2.5 isn't a huge jump.

Not sure where the o2 sensor was mounted.

Edit - plugged the paperclip into the connector flicked over to ignition codes weren't flashing - not sure if I'm plugging it deep enough? Trying to push it too far down without forcing it, it seems to hold inside without falling out but not getting any engine light flashing.

I guess best option is probably to just take it back to the mechanic

Cheers