Specia1k

Very new too posting but thank you for your time.

I have a BMW 545i 80k miles. No warranty, I am getting an increased emissions light along with occasional flashing but remaining ses light. Idles roughly misfire, also while driving I can feel it, not bad in park, worse in drive, shaking me and girlfriend with the AC on. A wee bit of smoke when going from stop too drive out of the tail pipe. Loss of power, massive loss after 60mph. Any ideas on problem? Rpm twitches at 500 with AC on at idle. Help please?

e6t.lab.rat

Your problem and solution here (courtesy of AGA)

http://www.atgruppen.dk/pdf/AGA-%20S...structions.pdf

There's also a video on youtube by the same guys.

Good luck

justanotherhemi

The misfires are causing your car to go into a limp mode which draws timing and power to keep the enginge from blowing up. Now the p0492 is a secondary air flow insufficiency bank 2. What this is is carbon build up in the exhaust ports that are causing your o2 sensor to read low hence the "increase emissions" code. I would suggest changing out you plugs for the misfires & do a seafoam treatment directly to the rear ports for the p0492 code.

marco211

The AGA would be your best bet, but I seafoamed it and it worked for me just depends on how much carbon build up you have. Here is the youtube link. I let it soak overnight, just don't pour too much as you run the risk of hydrolocking.

PAUL-E60

Can you give some detail on how to directly seafoam the rear ports? thanks

marco211

Like the video posted you can pour the seafoam through the secondary air pump hose that splits to each secondary air check valve. I poured 1/4 of bottle and let it soak overnight. Make sure you blow hard enough to get the seafoam through the check valves. After you start it let the seafoam burn out and then drive it at high rpm for about 5 mins to burn the loose carbon. If check valves have excessive build up repeat process. If you want to do it directly you have to remove the check valves and pour down the tube, but it's a lot of work because of the limited space back there.

Boost7

I"m going to give this a try but use BG44K instead of Seafoam......I'll report back to you guys once it's done.

BimmerFan52

For the N62 engine the main cause of carbon buildup is leaking valve stem seals.
Leaking valve stem seals are an expensive problem to fix, with the cheapest solution about $2500 if you can find a mechanic who will give you a discount.

The carbon buildup blocks small air passages in the block used to carry secondary system air through the block back to the cats to accelerate their heating during startup to reduce initial emissions.

If pouring a solution such as Seafoam doesn't work there is a procedure for pushing a flexible rod through the air passage from the rear of the block (a tool kit is available). If that also doesn't work the final resort is to drop the entire exhaust system (one piece) and remove the exhaust manifolds in order to manually clean the passages from below the engine (a huge project).

If the secondary air system is running, the system can be fooled to pass an emissions test, but this is only to be done for off road use and tracking the car. The computer determines whether sufficient secondary air is getting to the cats by measuring whether the system goes lean while the secondary air system is running. Adding air after the MAF only while the secondary air system runs will make the system think the carbon blocked passages are open and will not trigger an error. Drive plan must still be completed after clearing errors.

Erik Aguero

BMW N62 (545i, 645i, 745i) Secondary Air Injection fix