[azadani]

I'm with Ray on this one. I'm rebuilding an an engine from another make and was reminded while cleaning the head's carbon deposits how crazy difficult it is. I even returned a pricy gallon of the legendary Berryman's carbon cleaner and discovering that like Compound W, Oven Cleaner, and Rachel Welch, it's not like it used to be when it became a legend. Watered down. The only way I could see any compound cleaning your cats would be if you ruthlessly flooded the engine to near stalling with the product so it's splashing through as a wet mist into your exhaust system, and then I'd be worried about the grundge it's moving from the exhaust manfolds that is now flowing like lava to your already clogging cats.

I know you only wanted to hear from folks who've actually tried it, but thought it might also be worth hearing from folks who have been in the next lane over from the " cleaning with chemicals lane" with a wire brush in our hand that grasp the magnitude of that work and the truth of it working. Many people lay claims to things working online because they've become mentally invested in it since they did it, and if they hold their head just right, and the lighting is perfect, and the only second opinion they got was their girlfriend - that paint job they did in the garage looks "super dooper awesome, man - you should try it!..." Cough...

No problem at all.

I'm not one for psychosomatics, so it'll need to work for me to say it does.

I've made up my mind not to try this.

 

[azadani]

Just trying to help. I'm not one to promote chemicals, my 65+ years has taught me that they are just a band aid.

This might be one of those times when OBD Fusion should be used to build you a chart of the actual sensor activity. You can go on Amazon or eBay and get an ELM-327 module, then go to the app store for your phone and get OBD Fusion for 10 bucks. You get graphing capabilities of every sensor.

No worries, all good.

I have OBDFusion. Before that, I was blissfully unaware that my cats were questionable lol.

 

[Bdave]

My E46 M3 sat for a while and the fuel system and injectors were very much varnished and not working properly. Everything nasty. Car was stalling. Sucked.

I put in a bottle of injector cleaner with high concentration of Polyether Amine....PEA.

I bought Redline injector cleaner in bulk on Amazon and save quite a bit of money. REDLINE is supposed to have the highest concentration of PEA. Can't find Red Line? That means you don't live in good old USA. If you live in USA you can get Amazon and you can get very recently price Redline fuel injector cleaner in bulk.

I believe Chevron injector cleaner is also supposed to be quite high in PEA as well.

Did it work? YES!!! Perfectly. Everything tank full my motor got better and better.

Be agressive. Use a bottle EVERY fill up until no improvement is seen.
Took a few months for my bad case.

Make sure you replace your fuel filter before you start this process.

Could I have paid for a forced injection cleaning or rebuilt injectors? Possibly. This was easier and money spread out over a long period of time.

My sixteen-year-old injectors are working awesome. Car has more power than ever. I don't know why, but the rings are still tight and I don't burn a drop of oil between 4500 interval oil changes.

I continue to add a bottle of Redline fuel injector cleaner once a month.

 

[azadani]

My injectors were serviced professionally, and a brand new filter fitted with new vac/fuel hoses. My fuel pump passed the test but marginally, and I have a new one coming.

I'm really suspecting post cat sensors as having something to do with this.

 

[MrMCar]

When I rebuilt my head several years ago, I tried all kinds of things to clean the parts, including Acetone, Lacquer thinner, Mineral Spirits, and several other things. Full-strength, with soaking and scrubbing, most of them would not even touch the light brown oil residue in the cam valleys, much less the residue in the exhaust ports. The ONLY thing that worked on the exhaust ports was a Dremel tool with a small brass wire brush. I have a REALLY hard time believing any of them would do diddly for the fuel system, and even a harder time believing ANYTHING will have any effect whatsoever AFTER being burned in the combustion chambers. There is nothing left at that point but hot gasses. The original solvents are long gone. Really sounds to me like an old wives tale....

OFF Topic here:

Cleaning the brown patina:
P21S Total Auto Wash. Spray it onto everything, head, cams, connecting rods etc. Use one of those cheap bristle paint brushes from the box store and swish it around. Use the spray liberally. Wash with warm water and thoroughly dry.
It will BLOW your MIND!

I can put the above in one of two parts washers and still see the brown. Yet this paint safe spray soap, PULLS the brown RIGHT OFF!

P21S Total Auto Wash

P21S Total Auto Wash - Replaces a shelf full of other cleaners!I first started using P21S Total Auto Wash in 1988 as a general purpose cleaner on my first Porsche. On the exterior, I used it as a tar and bug cleaner. Under the hood, I used it to clea...

www.autopia-carcare.com

Been cleaning engine parts with it for 20 years. Want to go a step further? Place them in the dishwasher. With a 2nd. rinse. Just be sure the wife doesn't see.

 

[TobyB]

Better than Oil Eater, ya think?

t

 

[MrMCar]

Better than Oil Eater, ya think?

t

The stuff is amazing. It's also re-bottled as HondaBrite, safe on any paint and used for cleaning the entire motorcycle. I've used it for decades to clean the engine/engine bay. leaves NO residue.

By chance I tried it on the underside of a M20 Valve Cover during a valve adjustment. (Remember those?) I was brought to joy when the ugly brown inside looked like it was in for the 1,200 mile valve adjustment.

I do a lot of classic BMW engine rebuilds here. After all the disassembled aluminum parts get finished up in the parts wash sink, they're brought to the large wash tub I have in the employee bathroom.
Spray the P21S on and swirl around with a $1.99 paintbrush. Rinse completely in hot water and then blow dry with a blow gun.
Bam, 20+ years of brown patina GONE.

 

[mrkprsn]

The stuff is amazing. It's also re-bottled as HondaBrite, safe on any paint and used for cleaning the entire motorcycle.

S100 Total Cycle Cleaner | S100 Cycle Care Products

If you’ve been using a bucket of car suds or a quick detailer, chances are you been missing the most important and threatened places on your bike…those hidden nooks and crannies where dirt can hide.

www.s100.com

I think this is the same or similar stuff. It could be from the same company. The bottles and websites look similar. For motorcycles you just spray it on and then hose it off with water. You can use it on cars, trucks, snowmobiles, etc. It comes from Germany and was introduced a year later (1985) than P21S (1984).

P21S® Auto Care Products - P21S Auto Care Products

www.p21s.com

 

[mrkprsn]

I bought Redline injector cleaner in bulk on Amazon and save quite a bit of money. REDLINE is supposed to have the highest concentration of PEA. Can't find Red Line? That means you don't live in good old USA. If you live in USA you can get Amazon and you can get very recently price Redline fuel injector cleaner in bulk.

I believe Chevron injector cleaner is also supposed to be quite high in PEA as well.

Do you mean Redline Complete Fuel System Cleaner and Chevron Techron?