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so i replaced spark plugs, new head and all other gaskets, new TPS,cleaned my pistons, head, egr ports, throttle body, iacv, FITV, changed the oil, tranny fluid and coolant, and i took my car in for smog and my CO levels are high so i failed,
im trying to find ways to lower my emissions, now i just cleaned my egr valve,(which was really gummed up)took my injectors off and cleaned them, replaced O2 sensor and replaced ignition cables. what else should i do before i take it back for a retest? thanks any answers or suggestions are much appreciated,95 accord lx wagon
4 cyl. 2.2 non vtech
A/T
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High carbon monoxide readings are typically a sign that the engine is running rich. On the simple and cheap side of things I’d first make sure the air filter is clean and unobstructed. You’ve already replaced the TPS and O2 sensor, but a bad MAP sensor can make your engine run rich as well. A bad PCV valve can sometimes elevate CO readings if you’re getting a lot of blow-by.
I can’t see you pic, but if your HC and NOx are also elevated, it could simply mean that you catalytic convertor is headed south.
yeah forgot to mention new air filter, pcv valve is good and clean, and havent tested my map sensor at low speed my HC is at 17 ppm (average is 25) and NOx is at 130 (average 137) and CO is at.52% (average is .09%) (max at .34%) so im just a little over the max
I don’t know Hondas that well but the first thing(s) that I would look at is Rich fuel mixtures for incomplete combustion….map sensor sending the wrong info to the PCM… low engine temperature… fuel pump pressure regulator…a Honda person will fill you in on that.
Do you have a scan tool to look at?
ill test my map sensor, no i dont i thought since its obd1 i can only connect the jumper (which isnt giving me any codes)
And i did replace the sensors and clean egr valve after i failed so im wondering if i might be safe to retest cos i just need to lower CO a little bit
Depending on which state you are in. If you spend over a set dollar amount in order to get the car to ‘pass’ emissions? Then you can get a ‘pass’ which is good for the year. NYS does this, not sure about others. If your area offers this? Hold onto your receipts for parts and such.
Also it pays to know someone in the industry that has an exhaust ‘sniffer’. So you can have them probe the tail pipe prior to going in for inspection. (Sometimes local mom and pop shops can do it for you cheap….beer money or cig money….)
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I dont think california has that their pretty strict here,and i have a free retest, So im just trying to get as much fixed without replacing the cat, cos if i gotta replace that then im just gonna find someone to pass my emmissions, im just hoping the cleaning and new sensors will help lower my CO just enough to pass
California does indeed possess a process for granting extensions, if you spend over a certain dollar amount trying to make your vehicle smog compliant. It’s a painful process that most people won’t qualify for… and on top of that, all repairs must be performed by a state approved smog repair center. Which doesn’t apply in your case.
Anyway, considering the work you’ve done so far (and based on how narrowly you missed the mark), I’d definitely try retesting before replacing anymore parts.
Good Luck
Ahh i see yeah i cant bring myself to pay for a mechanic id be well out of over a $1000, but if i do fail i will pay the 50 bucks to diagnose it so i can at least know whats wrong or if i need to just get a illegal smog
But thanks i appreciate the responses, im crossin my fingers hope i passI’ll start by saying that Honda’s don’t like aftermarket parts. They hates some worse than others. In short, NGK and Denso stuff is a good alternative. Bosch is not. Aftermarket ignition parts on Hondas can cause misfires which can lead to high CO emissions.
That said, the O2 probably did the trick. Don’t mess with the MAP sensor or any other sensors. EGR is only active under load and has nothing to do with the CO readings. As pointed out that’s a rich condition. The O2 was a good place to start with this since the older systems weren’t as good at picking up a lazy sensor. You also want to make sure you don’t have any vacuum leaks. If you do, it can actually cause the engine to run rich because it’s trying to correct for a lean condition.
More info here.
http://www.ericthecarguy.com/faq/solving-automotive-performance-issues
Good luck and keep us posted.
I agree with Eric. High Co is caused by a rich condition and chances are good that by replacing the o2 sensor you have corrected the problem. Usually if the converter is tired all the gases will be high.
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