Another misfire thread

[SLeal]

So i have a 3.slow that intermittently shows a cel. When vag-com'd it says I have random misfires on cylinders 2 and 4. I recently replaced all spark plugs and replaced the coilpacks on both cylinders 2 and 4 but I still get the cel and the same codes come up when scanned.

Tell me I'm missing something simple or that I just have to clear the cels...oh yeah, and my secondary air injector is throwing a code too...after poking around I found the plug to the pump disconnected and plugged it in but again, the same code comes up.

I have the shareware version of VCDS lite and an ebay cable and have yet to pay the $100 for a legit copy and am holding off as long as I can lol

[SLeal]

Anyone?

[CyberPMG]

Could be lots of reasons that cause the misfires. You've already replaced the ignition coils and spark plugs. Check the MAF. Could be that the element is dirty and needs cleaning/replacing. Check for vacuum leaks. That could also lead to random misfires.

Are the random misfires the only codes you're getting? Did you do the replacement with new parts or used parts?

[SLeal]

Thanks for the reply. I replaced with all brand new oem parts. I'll have to double check but the codes Im getting are random misfires on cyl 2 and 4 and a secondary air injector error. I'll check the MAF tomorrow when I get home and look over the vac system again

[lyleswk]

I would lean toward looking at the SAI since you have a code and that could be messing with the air side of the mixture. Anyone think that sounds off?

[SLeal]

So after cleaning the MAF sensor and rescanning I still have the same faults.

SAI pump airflow is insufficient to bank 1
Multiple/random misfires with improbable readings - cyl 2&4

Would I find more info if I had a registered version of VCDS lite?

Like I said before, I plugged the harness back into the SAI pump but it didnt seem to do a whole lot cuz im still getting the same code

[CyberPMG]

If you're not hearing the SAI kick in on a cold start, then it's likely that the SAI needs to be replaced and would address some of your codes that you're getting.

[SLeal]

Im not even sure what to listen for. Is it clearly audible from a distance? Should I get close?

If I have to replace the damn thing... I've been replacing parts left right and center since I bought this car and am getting tired!

[CyberPMG]

Sounds like a hair dryer turned on. If it sounds like a loud leaf blower, then the bearings are shot and needs a replacement. If you're not hearing any type of fan sound kick in on a cold start and then turn off later, it could be the SAI or the relay that turns it on and off.

If you have VAG-COM, you can do a relay check which will cycle through all relays including the one for the SAI. When the test is done, you'll hear the SAI come on and off over and over until you stop the test.