curvy95honda

Smog failed and car runs poorly

So, here’s the problem…
Cruise Control does not work.
Low idle in or out of gear. 400-500 rpm (sometimes acts like it’s gonna’ die)
Car is running poorly, bad response.
Bad MPG.
No power, sluggish.

A few months back I had to get a smog test and it failed. Here are the results;



So, I took the car to a mechanic and he said I needed a new catalytic converter. No problem, shelled out the dough and he “got it” to pass. Here are those results.



2 years ago, when I had to have it smogged, it failed and the mechanic “got it to pass” by replacing the o2 sensor. I have those pre/post results too if needed.

The problem persists so, I have been trouble shooting and chasing some various symptoms changing and updating parts along the way such as;

Full tune-up. Plugs, wires, cap, rotor, ignition(recent), etc.
New Water Pump, new Timing /AC/PS/Alt Belts, New PS Pump. (it just needed these)
New Crankshaft and Camshaft seals.
New Fuel Pressure Regulator, Main Relay, Stop pedal switch.

Checked the vacuum pressure at the service port while idling – 42 psi

When I pulled the spark plugs this last time to replace, they were coated in a white powder. A friend told me it was from running too lean. So, that is why I have been chasing fuel system components like the main relay, fuel pressure regulator, etc., however my problem persists.

Does anyone have any insight? At this point I am frustrated and don’t want to take it to the stealership, only for them to “chase” the problem at my expense.

flush_EJ1

What engine? Is it the original motor or a swap? Can you post the most recent test results?

grumblemarc

iTrader: (4)

Check your ignition timing?

curvy95honda

What engine? Is it the original motor or a swap?

D16Z6 - This is a swap but for the exact same USDM D16Z6 out of another 95 Honda.

I realize now I did not post the info on the car originally. This is a 1995 Honda Civic EX Coupe - 4AT made in Canada with a D16Z6 engine

Can you post the most recent test results?

The most recent test results are posted. Above, the pic that says "pass" is the very most recent (about a month ago) and the one that says "gross polluter" was just before the cat replace (about three months ago).

Check your ignition timing?

Timing is set at 16 degrees. No problems there but I can't get it to idle properly even still.

JUICE66

That HC number @15 mph after the catalyitic replacement is still a bit still high, did he replace the o2 sensor then too? A cheap aftermarket o2 sensor will get you past the smog once then go bad and your cat can/will be ruined in the process. Most cat manufacturers recommend replacing the o2 sensor when you replace the cat.

Check the gap on the plugs and the o2 sensor, coolant temp sensor, thermostat, as well as the ECU back up fuse (under hood fusebox)

Honestly given the marginal HC@15mph after the cat replacement I'd say the guy who replaced the cat didn't solve the underlying problem that caused it to need a new cat to pass smog in the 1st place, but whatever is causing that to still be high can damage the new cat

EDIT: check if you are running too lean the HC will still be high - try the knock sensor

curvy95honda

did he replace the o2 sensor then too?

No, The last and only time this car has had the O2 sensor replaced was two years ago on the last smog.

Check the gap on the plugs

Just put brand new plugs in, gap is set at 1.1. Old ones looked really bad though for only being about 6 months old.

and the o2 sensor, coolant temp sensor, thermostat

I assume I have to check the resistance on the o2 and coolant temp sensors?

The thermostat is brand new (replaced with the water pump)

ECU back up fuse (under hood fusebox)

Any idea which one it is? The sticker on top of the box is gone and i cant seem to get a diagram? I did check all of the blade fuses and even replaced them just in case but the larger fuses all looked and smelled fine.

check if you are running too lean the HC will still be high - try the knock sensor

My last set of plugs had a bad gap on cyl. 1 but the rest were fine however there was a thick white powder coating the tips of every one of the four. I am told that means the car is running lean. Again, should i test the resistance on the knock sensor?

Honestly given the marginal HC@15mph after the cat replacement I'd say the guy who replaced the cat didn't solve the underlying problem that caused it to need a new cat to pass smog in the 1st place, but whatever is causing that to still be high can damage the new cat

I agree with everything you said, 100%. There is definately something still amiss with this car and I fear that i will be replacing the cat again if I don't find the problem.

Thank you very much for your help bro, I really, really appreciate it.

JUICE66

I'd just replace the o2 sensor - a bosch oem equivalent is about $40-50 and most cat manufacturers recommend replacing the o2 sensor when you do the cat. That should take care of any emissions issues but watch your MPG and see how it runs after you do that before going any deeper imo

the ecu and back up fuse are the 15A and 7.5 A on the top left, should look something like this-

rhymeshark916

A good o2 sensor will be more that $40-$50, more like $70. That's what I paid mine NTK/NGK OEM plug for. I think I need to replace mines again even though it's brand new because I can't pass smog on my B18c hatch with a new magnaflow cat. I ordered mines online at www.summitracing.com