Jayson Hurst

Hey guys, I'm not sure if this is exaptly the right place to post this, I'm new to this forum. Thanks for looking in advance.
I recently bought an all stock 99 integra gs 5sp. I knew it had a check engine light but it was running fine, and for 2000 I drove it home <100 miles with no problems.

Since, it has been running progressively worse. I pulled a code with an at-home scanner a few days ago and it was showing #2 o2 sensor code PO420.

I just took it up to a shop to get a better read. Here is the list;
-Misfires on all 4 cylinders
-PO420 O2 sensor bank 1
-PO430 O2 sensor bank 2
-42-1 front wheel lock (?)

I'm planning on making this my DD and doing small upgrades in the future, I'm wondering what I could buy here to put on my car with future interest in a small build and to get it running right again.

I bought a high flow cat, both o2 sensors and spark plugs since I don't know when anything has been replaced. When I take off my battery and let the ECU reset, the check engine light wont come on for about 2 minutes at idle, or if I drive it for a few minutes. When the light comes on it starts lagging around 2k-3.5k RPMS, leading me to believe it has to do with my sensors or a clogged cat and my computer compensating for the reading of my o2 sensors. What do you guys think?

thanks again.

thewrai6th

This could be a number of different causes, did you get P1399, P0301,2,3,4? Fix this issue first. P0420/0430 does not affect the engine operation.
Bank 1 is incorrect. This is set off by Bank 2. Usually bad cat, this code means that bank 1 was sending a fluctuating signal and bank 2 was expecting to see the same signal altered slightly and did not see anything in normal operating range. If you have a high flow cat, that is probably the cause. In your case, you need to resolve the misfires first.
Bad Cat, see above
No clue...

This part was a bit confusing. Did you replace those parts or not? If you're hitting a rev limiter at 3K, you're in limp mode from the misfires. Does the CEL blink at all?

trm4life

I know from experience, my car prefers copper plugs. Had a misfire issue with platinum, burned one up in a matter of months. Other than that, I don't think disconnecting the battery resets the ECU. There's likely a fuse that has to be pulled.

Jayson Hurst

I got all those codes my first read and cleared them. The second read a day after I got 1,2,4, and the random misfire. I cleared them again, the engine ran for about 1 minute and the CEL came back. Its shuddering at warm idle and mid range RPMs, as well as lack of power in mid range. I pulled the plugs out of the spark plug chamber today and they looked relatively new, along with the distributor cap and spark plug wires. I wonder if that route has already been taken to try and fix this problem by the previous owner. What do I do to fix this issue?

I just got all the parts together today, I haven't put them in yet. I'm not hitting any rev limiter, as said above. It only gets power to accelerate in the higher RPMs. The CEL blinks when I get into 4th or 5th gear and stays on until I turn the car off.

I just got ngk platinum. Did yours misfire right away?

trm4life

No, it was random. Drove my car into town, drove about a mile or two, parked at home and suddenly a spark plug just died. It didn't really do much other than sound like a Subaru. It would run better at high RPM. Personally, it sounds like your timing needs adjustment. Does your car use a distributor? I know with OBD 1, you have get to operating temp, shut down, jump a wire, restart, adjust timing, shut down, remove jumper. Also, the distributor systems have the crank sensor, timing advance, and ignition coil inside. I've actually had the screw fall out of the rotor 2× on two different distributors! Make sure to use light thread locker and a lock washer on your rotor! Oh, another thought, check your air intake, make sure it's tight, not cracked.

Jayson Hurst

I have OBD 2, it does use a distributor. Everything looks fairly new regarding the distributor, wires, and tops of spark plugs. I'm replacing plugs, cat, and o2, and see if it runs any better. After that, my direction would be to go towards a timing issue. When I replace my plugs I'm going to take a look at the inside of the distributor and see what I can find.

The air intake is an aftermarket cone, the housing doesn't seem cracked. I'm going to clean it out as well.

Jayson Hurst

I replaced the cat and hardware, both o2 sensors, spark plugs, and ignition wires..

and everything seems to be working properly!

I changed from 8mm to 7mm wires (since i didn't think it mattered much, most everything else is stock) the cat and the o2 sensors at the same time. After this it started working properly. I changed the plugs before this and it still ran bad, I know the cat was bad since it sounded worse than a rattlecan, but everything else was basically for good measure. At this point, I may put back on the 8mm wires to see if they still work (1 of the boots where it connected to the spark plug had a small tear, could that affect arcing or performance?)

Thanks again guys

trm4life

It may be something as simple as your ignition timing. I actually had an issue with my car, and had to readjust my ignition timing. I thought I had it right, seemed OK but was not smooth from 2-3k. Over 4k, the tach was lagging. Fine tuned my ignition timing and seems way better now! Otherwise, maybe your ECU or dizzy are getting tired. Make sure your coolant is full, and proper mix. Get to operating temp and try to get your timing dead on. Also, cheap or oversize wires (imo) are crap. Get a good brand name set, or buy the OEM ngk wires. I'm personally running accel wires with no issues.

17importcar

Hello I'm in a similar situation. Recently bought a stock 01 GS and it has been misfiring with codes P0300, P0302, P0304, and P1399 (comes and goes). No other check engine codes.

I have done the following:

New Denso plug wires and double platinum plugs
New cap and rotor from Acura dealership
One treatment of Lucas fuel injector cleaner with 91 octane gas
Valve lash adjustment .004 intake, .007 exhaust
Compression (cold) 1 to 4: 172 160 168 160
Fuel Injector resistance 1 to 4: 29 25 24 25
The injector wiring cover that bolts to the fuel rail is missing. When I yank and move the wires around it affects the idle.
Sometimes I hear the injectors click, sometimes I don't.
The engine makes a weird noise that sounds like something is frying on a pan with a lid on it. This worries me the most.
The CEL comes and goes. Once in awhile it flashes and when it does the engine shudders and hesitates, I get nervous and turn off the ignition.
The thermostat might be stuck partially open because it takes long to reach operating temperature, at least 15 minutes of driving.
Checked ignition timing with a timing gun and it is spot on at 16 BTDC

Average 28 mpg

What is causing the misfire?

wunfstgsr

​​​​​​​yes it can clear a cell or code causing limp mode.